I spend a lot of time on pricing and packaging of SaaS software and the challenge is real. Everybody says they want simple pricing, which often aligns to seats or MAU - but then they want usage-based pricing, but then they're concerned about unpredictable costs and spiky usage.

Unfortunately, there's no such thing as a free lunch - you can have simple and predictable but you will have some users that you pay for that aren't getting value. You can have usage-based billing, but then you run the risk that anyone who uses an antipattern for the product will suddenly cost you a ton (or consume all of their allocated quota and be dead in the water, which is differently bad).

The more flexibility you offer, the more complexity you're putting onto customers and sales teams to understand what's the best way for them to consume the software.

There's also a lot of market pressure to "follow the crowd" - even if you have an option that is (in your mind) more customer friendly/favorable, if you are structuring your pricing differently than the competition, there will be customers who are concerned that they're not getting "a good deal" or concerned that the structure will end up being less favorable to them over time (after all, why does everybody ELSE do it this other way?). Sales reps also prefer pricing strategies that are at least structurally consistent with other products on the market, because it makes their lives easier.

Similarly, it's very difficult to change pricing nad packaging later on - changing price is relatively simple, but changing units of billing or retiring an old offering can be an extremely difficult task.

(disclaimer: these are just my own opinions, everything is hard)