It's up to you and it's on a case-by-case basis. To me, they tend to fall into 2 categories that I personally think of differently.
My take is that if you were under-utilized, stuck behind someone else, or just generally lacked playing time, go where you think you can get what you want. Wargo in baseball. Didn't play much, but contributed when he did. Next year was supposed to be his year to start but Jose had a breakout year. Hate to lose him but wish him well.
If you are leaving chasing NIL, a bigger name University, following a coach. It's a business. Save your social media post (that's mostly self-serving, anyway.) Pack it up and move on. It's about the name across the front of the jersey and you don't represent our university anymore. Think Zeon, Lacy, Brown and now Davis.