Unless you're a teacher, the rest of us are expected to work year round and I too have a family.
For some of them, this better training could net them millions, upon millions more money (which is why some pay for it and go do it themselves). Do we think Orelvis is oblivious to the holes in his swing and doesn't realize that without fixing them, he may never make the majors or earn any real money? You think he's just like "f*** it - I need 5 months off this offseason to go spend time with my family". Or he thinks "I'll just do some at home workouts and have the boys toss me batting practice on the sandlot and I'm sure that will fix the problem?"
In the LONG history of baseball - it's never been easier for top athletes to identify and fix their flaws. I understand the season is a grind and I'm sure the high performance team would want to structure in rest for their bodies, but I don't think it's unrealistic for a team to expect them to spend portions of the offseason working to improve their game.
LA sent Mookie Betts - why isn't Toronto sending Vlad?