Later this month your Guardians can continue their Destiny 2 journeys on whatever platform you see fit, as cross-save launches on 21st August.
As well as cross-save, on 20th August Destiny 2 will begin it’s migration over to Steam, allowing players to start linking their Battle.net and Steam accounts “to facilitate the transfer of content on 1st October”.
Unfortunately ‘cross-save’ does not mean ‘cross-play’ – while your progress will save across accounts, if you want to play with friends who are on PC you’ll need to hop onto a PC too.