Yoda is not just a crazy alien for the sake of it. first of all it was an experiment in animated performance. people forget that once upon a time the idea of having a puppet onscreen as a main character in a mainstream film just wasn't done. that was for silly monster movies and such. the idea it could elicit emotion & a belivable performance that one could get lost in, that was also laughable. it is a testament to the hard work of Mark Hamill and the entire crew, who lived on a swamp set for months, alongside snakes and bugs and other critters, filming this experimental sequence where a puppet discusses metaphysics in a blockbuster children's movie. the technology to do this didn't even exist so they had to fund it themselves. all that was incredibly risky. the new films don't try to do anything close to as insightful, revolutionary, warm, and welcoming as Luke's time with Yoda. just empty platitudes about legacy.
secondly, Yoda is not just a random green alien guy. his character is partially based on a Kurosawa movie out around the time of writing
Empire,
Dersu Uzala, which featured a strange old man, living in the wilderness, who spoke in a backward manner of speaking, and was a lowly looking person, yet had great wisdom. there are plenty of Kurosawa references in SW of course, and the word Jedi even comes from the Japanese word for these films.
there is a lot of thought & reason behind George Lucas's stuff I think is getting brushed over in order to prop up
The Last Jedi. who is Holdo based on? has Rian given an interview on that? i'm not sure, she seems like a character device to me, with poor, shifting motivations, there to give Rian's poetic speeches about sparks & suddenly (compared to the last movie) paint the Latino leading actor as a swarthy, sexist, dangerous, untrustworthy man. has anyone looked into the weird way Rian launders his perhaps unexplored Latin stereotypes through his male feminism?