Only when he's being nerfed massively like he was in the Rukia Fight.
He ate 33,650 different hollows and gained their abilities. That's a stupidly high number and by all rights he should have murdered Rukia easily.
Let's assume identical abilities don't stack, because then he'd have enough regeneration to come back from paste and massively increased Spiritual Energy.
He can almost certainly fly, burrow, launch all sorts of unique Ceros from numerous body parts, has the strongest High speed regeneration of any hollow he's eaten, the toughest Armor, and most abilities you can think of.
If he manages to use his Resureccion on us, his only problem will be how to kill us.
Im not so convinced he has all of them everywhere. His ressurection dosent seem to be "the strength of all these thousands", and more resemble "30.000 base hollows and lots of duct tape".
Well, not entirely, but its utterly bloated, and it seems unlikely everything is everyhwere. For example, IIRC we have it confirmed somewhere, that while he has metastacias zapakuto-shattering power, it dosent happen when you touch his body, only if you touch some specific small bit that sticks out of the mess somewhere. Firing numerous variants of base-hollow level ceros on mostly random direction because most parts point away from the target is a much less daunting prospect.
Also, it seems that his head remains a weakspot no matter what. (Although roses head at least is likely less fragile, it can still be aimed at)
From what I remember, Triple-A's Ressureccion allows him to access the abilities of every Hollow he's ever eaten simultaneously instead of only one at a time (which is what he's normally limited to). How useful that is, however, depends on a few factors.
The first questions is how well Triple-A can use each of his powers. Just because he has (for example) the ability to shape rock into drastically oversized spears and hurl them at people, doesn't necessarily means he's any good at it. He might have poor aim, or be slow at activating it, or run into any number of other issues that someone who's trained with the power would have overcome. And normally for a power like this I would probably guess that would be the case... except that when Triple-A is playing at being Kaien, he shows he has all of Kaien's memories and fights exactly like him to the point Rukia can't tell the difference between them. And although this doesn't
prove that Triple-A can automatically use his powers with the skill of the original- you could argue that Triple-A realised how useful Kaien's powers were and focused on copying Kaien's skill, for example- outside of evidence to contrary, I'd say that it's more likely Triple-A simply gains the original skills and experience of the Hollows he consumes.
However, as is shown so often in Bleach, if an ability doesn't have enough spiritual power behind it you might as well be spitting at your enemy. And thus comes the question of whether or not his stolen abilities scale to his level of raw power, or if they stay stuck at whatever level their original user was at. If it's the second then his threat level is drastically lowered, as he's most likely been eating primarily base Hollows who have correspondingly weak powers. But if it's the first, and his abilities scale with his raw power... well, that basically means he's going to have the perfect counter for damn near anything anybody in his own weight class or lower can throw at him. And unfortunately, there's no way to know- the only ability we see him make active on-screen use of is Kaien's Zanpakuto when fighting Rukia, and given both Triple-A and Kaien outclass her it's impossible to say whether he's using it at Kaien's level or his own (potentially lowering it down to better mimic Kaien).
And lastly, we come to the question of multi-tasking; just because Triple-A can
access all of his powers at once in Ressureccion, doesn't necessarily mean he can
use all of his powers at once. Whilst there's not actually any direct evidence for it, it wouldn't be unreasonable for a power like his to have issues with identifying and finding specific abilities that he wants to use out of his 33,000-odd collection, or for him to be unable to split his focus enough to manifest more than a few active powers at once, or for using non-similar powers simultaneously to be more difficult than using similar ones (for example: he might be able to use any number of powers that do the same thing at once without issue, but find adding in different ones extremely difficult), and so on.
However, as I mentioned, although it would make sense for those sort of limitations to exist? There's absolutely zero evidence of them; Triple-A could very well have no issues at all with using as many different and varied powers as he wants at once. We simply don't know- he never tries to use his powers en-mass on screen. But if he is capable of using all of his powers at once with no issue... well, then you could potentially get things like him zapping somebody with three-hundred and ninety-eight lightning powers all at once, whilst simultaneously dropping down six fields of slowed time around them and using his two-hundred and thirty-seven ice generating powers to create walls to hem them in on top of that. I don't think I need to elaborate further on how nasty that would be.
In conclusion, Triple-A is potentially very scary. But exactly how scary depends far too much on factors we simply don't know and don't have information on, which ultimately puts it in the hands of Omicron.