@Yahya Not sure about MK 11, but as for Destiny 2, the dev mentioned that it's something they're thinking about, but have no real plan as of now. Personally, I don't think it will happen anytime soon. They already stated that they're constantly under crunch trying to deliver content and trying to scale down. I don't believe they have the manpower to work on cross play.
Mk11 runs so well for me on stadia but I regret purchasing this game and wish I originally purchased on the PS4 bc stadia literally had 0 online players. I can sit waiting for an hour in match making and not a single match is possible most of the time. I've only had a little bit of luck when it launched and even then I'd have to wait for 5-15 mins. Very sad and I would of requested a refund if possible and just purchase it on the ps4. My ps5 will arrive between Nov 27-Dec 2nd and i might swallow it and just buy it again. 🥺