I feel like we're jumping on @edaydeveloper for asking their question just because they could have googled some of it. Someone with an anticipated problem is looking for a pre-emptive solution, what the solution actually should be is up for debate, regardless of which solution currently LE wants to support.
I know the thought of having paid features is anathema to many in the community but for those who actually want to do the paying it's just that they're trying to find a way to avoid artificial roadblocks that they can plainly see ahead. Can they fill out the rate limit form in advance of starting their rollout to customers? We know the current rate limit extension process involves batch updates which don't provide immediate results. Obviously nobody wants to implement anything that will negatively impact other users, so there's no suggestion that paying users should be allowed to abuse the API etc.
The topic of paying for pre-emptive rate limit increases came up again recently: Please give an option to pay for extra rate limit
We can also argue that all users should be reading the docs and adjusting their strategy instead of trying to pay for the problem to go away, but knowing all about the rate limits doesn't make them go away.
The implementation complexity/administration of providing payment infrastructure is anticipated as a big deal but the reality is a Stripe/Paddle subscription purchase link coupled with a webhook for activation is not especially onerous and at (for example) $24.99 at month for 1,000 special case users you get nearly $300,000 USD of extra income to support/improve the LE service as a whole (2 extra staff or additional cloud budget perhaps?).
Much is made of the difficulty in funding open source and open services in the OSS community (I have this problem myself, especially for https://openchargemap.org), so walking away from people with money in their hands is something it's worth thinking twice about unless you're supremely confident your major sponsors will never dry up, especially if accepting that payment doesn't compromise any specific ideal the project was founded on. Nobody is suggesting LE certs should be paid for, but the rate limits are a very obvious way of adding value (even if they people paying for pre-emptive extensions never use them, they just see a potential problem and are looking to pay for that safety net).