Vegeta's posh attitude

[Yuji]

Vegeta went from a barbarian who'd eat his opponent's corpse and would use underhanded tactics such as throwing dirt in his opponents' eye, to being this posh, proud aristocrat who snarks at eating bugs and is afraid of worms. In general, his mannerisms also changed, with his feminine leg cross and other more queer-coded gestures.

I think this change in characterization started around the Android arc as his princely side came out more. But besides Toriyama thinking it was funny to juxtapose a snobby aristocrat with Goku's low class lifestyle in comedic situations, would there be an in-universe reason for this change?

[Chuquita]

Freeza. Even though Vegeta hates Freeza, he lived under Freeza's control for 30 years; his childhood, teenage and young adult life; there's a subconscious impact made on him about power and how those with power act.

Much of Vegeta's physical posh gestures are in the same vein as Freeza's even though he obviously doesn't speak aristocratically like Freeza does.

[Yasai9001]

Vegeta went from a barbarian who'd eat his opponent's corpse and would use underhanded tactics such as throwing dirt in his opponents' eye, to being this posh, proud aristocrat who snarks at eating bugs and is afraid of worms. In general, his mannerisms also changed, with his feminine leg cross and other more queer-coded gestures.

I think this change in characterization started around the Android arc as his princely side came out more. But besides Toriyama thinking it was funny to juxtapose a snobby aristocrat with Goku's low class lifestyle in comedic situations, would there be an in-universe reason for this change?

I suppose the in-universe explanation would have to be that Vegeta eventually realized there is far more to life and also came to the realization as to precisely how grotesque some of the things he did was (like eating live humanoid bugs and things of that nature); for example, let's say in the real world you grow up in a neighborhood that glamorizes war, wrongdoings, and lawlessness above all else - you don't have nor remotely understand the simple luxuries and most basic accommodations of life and your parents probably care about you just enough or a little bit. Vegeta only was raised how to fight since he was a kid - not just fight, but kill. Some people in real life don't even move out of their own block. Being twenty minutes or thirty minutes out of the way is "out of town" to them. A lot of simple things can be foreign to people - like there are real life people that have killed yet never lost their virginity and never will since they're either locked up or dead.

Vegeta likely didn't get to experience pleasantries or happy feelings of GOOD and a GOOD TIME (his idea of a good time was beheadings, cracking bones, breaking skulls, and snapping necks) - no television, no parents to read him to sleep, or be held by his parents like a child would want to. He practically had to raise himself. Had no father figure and had to look up to Freeza and others for guidance in regards to strength, and if not them, then himself. Showing weakness as a Saiyan was already looked down upon. Being the prince of a warrior race? He had to be the most ruthless, callous, and prideful Saiyan there was.

Being on Earth and getting to see how simple life could be likely had an affect on him. Bulma was also a big reasoning for that and probably showed him the better side to life. A vacation for Vegeta back then was probably akin to sleeping in his pod until he got to the next planet or just standing around while Nappa, Raditz, and their two unnamed comrades took care of most the dirty work. And even though Freeza could have all different types of food from different worlds within his organization, Beerus and Whis have shown us time and time again that nothing...and NOTHING...compares to Earth's food. The meals are so delicious that Vegeta has refined his taste (he's real bougie now lol).

Vegeta's mid-life crisis probably revolved around in not just Goku being stronger but realizing that so many people have had it easy while he was working for the man who slaved him after destroying his home-planet; having to think back on your own past with the full picture really can mess with one's mind and having the support of Bulma and maybe even others helped Vegeta a lot, but he's just too prideful to admit certain things.

I hope this makes sense to anyone reading.