Nowadays, cross-play and cross-save are highly common features. It's easy to play any game that's supported with the above mentioned functionalities on, for example, Nintendo Switch in handheld mode while commuting, then after getting back home, change to PC and still keep playing with the same save file. However, it seems that the same case can not be applied to Monster Hunter Rise.
With the PC version of MH Rise is launching in January 2022, Capcom earlier announced that they are unable to implement cross-save and cross-play features for the monster hunting action title this time.
"We've heard your requests for Cross-Save / Cross-Play for #MHRise & #Sunbreak, but unfortunately, after looking into it throughout the development process, we found we are unable to implement it this time. As always, we appreciate your continued feedback and support", Capcom wrote on Twitter.
So, you might want to reconsider whether you are ready to start all over from the very first beginning if you've already got the Switch version of Monster Hunter Rise but also have been thinking about getting the title on PC as well.