Having both systems with both "full tier" subs, I go Xbox.
I'm not sure why, but the kids gravitate towards it more, even though I can put a lot of the same games on either thanks to the subs, and they're part of the equation for me.
If it was just me, then it's a much tougher choice. PS5 top sub gets A LOT of good games across a wide span of generations. The problem though is that it relies heavily on streaming instead of emulation so if you're in a place without good infra that does you no good.
The Xbox wins a bit in its favor by having a Sony game (MLB The Show) on it's Game Pass where even with a top PS+ sub you don't get it on PS5.
Both have great exclusive offerings IMO, so its really what platform has more of what you want for a price you're willing to pay.