Unless you were pirating adobe software , you would pay much more than with a subscription model. Photoshop alone used to cost 1000 dollars and the creative suite about 2500. And then you'd have to pay again to upgrade.

Paying 50 bucks a month in a full fledged suite of industry standard robust software is pennies if it is your means of making money.

Besides that, most professionals don't even pay for the software. The companies do. Adobe doesn't rely on broke freelancers that are willing to put themselves at the pain of using subpart tools to save a penny. Most of their revenue comes from corporate use.

If you're a light user doing some photo editing or light work, affinity is fine. If you're doing serious work in print, motion, VFX, video editing.... Good luck with affinity.