Never assume free tiers will last forever. Recognize they are often a way to entice people into the system. And that often they change as the business grows. Thus don’t build your business that depends on free tiers.
Discount stocks brokers make more money on float than trades.
Search engines make enough off ads instead of charging per search.
Photoshop didn’t have a free tier, but rampant piracy from home users created proficient corporate users.