With TOGAF a lot of architects always restate KISS, however being simple is actually not simple as there are aspects of being simple that are plainly awful. Example for being simple are using flags instead of value pairs, create a new structured customer table on a micro service instead of reusing the existing enterprise wide schema, using actors rather than roles or just being lazy and declare micro services as the same as services. This kind of simplicity is actually dangerous and is sadly often something seen with some older architects as it is often also labeled experience.
Good simplicity is to reuse things and acknowledge that others are as good as you or even better. Good simplicity is actually not complex, it is just something done in a team not by someone’s ego (not to be mixed with design by committee), as it is important to have the design checked to avoid developing your own logic instead of reusing common math equations. As such good simplicity is all that is still simple to a team and not only to you and me.