I think it is safe to say we might need a bit more information to make a good suggestion here. Like how much storage do you currently need?
As said by others AWS(also GCP and Azure) can get really nasty with lock in(both egress fees and their specific offerings). All 3 are also US based so there is a chance they shut you down because they don’t like the content.
Happy to discuss it a bit more and see where I can help.
Thanks for that additional info. I’ll poke around a bit and see what I can find since you also mentioned hosting Matrix(I run an instance personally so will check usage info on mine). I’ll fully admit most of my experience is with the big 3 cloud companies, at least professionally.
I’ll also echo what another comrade mentioned in that a CDN would be helpful here.