Regular small updates help site owners see if the updates create more bugs and if so can help solve them. If someone has dozens of different apps from different vendors then they can trace the issues faster than say an update that has over 300 changes. Before 13 UNA rolled out updates that were easier to track and quicker to fix and developers could also catch up and update their apps. Bigger longer updates break sites completely and costs more for the site owners that have to wait for mod developers to sort out and update. If you have custom work done it's even harder and more costly. There really is no such thing as "wait until all bugs are fixed" because updates always create more bugs.

what @Will Roberts writes was also my speech before and I can only agree with him. It is not possible that we wait here half a year or 3/4 year wis a release appears. You should not underestimate the costs if you roughly extrapolate everything in the month, (with streaming) and (without third party modules buy) then just 300 - 400 euros go here.

There are no such things "bug free", its just part of updating and changes, really.