If we get even a million daily users it's going to be an issue.
Pretty sure.
And any frontend can just onboard with an email and password if they feel like it, storing the keys themselves and giving themselves permissions. Lite accounts already do this by design.
It also depends on the app.
If users are posting app commands directly on chain it could get crazy very fast.
Just like how Splinterlands gave us the crunch however many months ago that was.
Well that would be 100x or so from where we are now. 😎
But, yeah, accounts and active accounts are very different things.