This is really not true. Since the end of lockdown, in La Liga, out of the 11 matches they played, Bale was in squad in 10 of them (was not only in the last one). Sure, he played only in 2 matches, but he was in the squad in another 8. In the last UCL match before this (City at home), he played. Not counting matches when he was injured/suspended, he was not named in the squad only 3 times before this match (2 of which before the lockdown). It is not that much different from Jesse Lingard who was not named in many more matches, and was an unused sub in some other matches.
I guess, if a player is happy to collect 30m per year playing golf all day long, he should actually do the bare minimum (go to training and travel with the squad when asked). Sure, he might be a glorified mascot, but he can easily decide to quit Madrid and reach a deal. This might give to Madrid a cause to try to terminate his contract.