My feeling about SAFe can be described in the following words of Robert C. Martin:

«It's a sad fact of our industry that the names of good things pretty quickly lose their meaning because people steal those names, in order to steal the good reputation.»

It does not assimilate anything, it just steals names.

It looks like that anything that might sound cool, should be put inside so when the executive X, Y or Z arrives, he can found whatever he felt trending inside.

The reality that I found is that often SAFe is an excuse to change nothing, or to adapt things, so some few executives feel good about themselves.

For example, around four years ago, SAFe was imposed in which was my team. The productivity drop around 10x. The first reason is that some things are difficult to plan, if they are complex or unexpected, and react fast in most SAFe implementations is hard, or impossible. The second is a strange phenomenon that I call "tic-tac" in which taks are alternated between PI, so you lose all the continuity. And probably the worst, is the big number of times that PM and PO come with a super-important-task that has to fit to an entire PI, without speaking with the team, just to discover and the end of the PI that those tasks were useless, and you have to throw away.

SAFe steals the name, and kills the spirit.