Telling the customer that "we are SaaS and we will distribute all updates on our schedule" is really convenient for the provider. However, is that really the best service to your clients?
It's significantly better for us as a team to be able to focus on projects and improvements that benefit everyone. I've noticed the business starts to suffer when we focus on individual clients with narrow needs. Any one client only brings in 1/4000th of our revenue, so spending 1/4 of our development capacity on just something for them is a huge opportunity cost when we could be using it on something that benefits all our customers.
It was a different ballgame when I worked on on-prem software that cos millions and we only had 10 customers with a few customers sharing the same version.