The Claude MD is like the documentation you hand to a new engineer on your team that explains details about your code that they wouldn't otherwise know. It's not bad to need one.
Consider that every time you start a session with Claude Code. It's effectively a new engineer. The system doesn't learn like a real person does, so for it to improve over time you need to manually record the insights that for a normal human would be integrated by the natural learning process.
Yes, that's exactly the problem. There's good reasons why any particular team doesn't onboard new engineers each day, going all the way back to Fred Brooks and "adding more people to a late project makes it later".
I certainly could be updating the documentation for new devs very frequently - the problem with devs is that they don't bother reading the documentation.
If you are consistent with how you do your projects you shouldn't need to update CLAUDE.md nearly every day. Early on, I was adjusting it nearly every day for maybe a couple of projects but now I have very little need to make any adjustments.
Often the challenge is users aren't interacting with Claude Code about their rules file. If Claude Code doesn't seem to be working with you ask it why it ignore a rule. Often times it provides very useful feedback to adjust the rules and no longer violate them.
Another piece of advice I can give is to clear your context window often! Early in my start in this I was letting the context window auto compact but this is bad! Your model is it's freshest and "smartest" when it has a fresh context window.