There are many, more imaginative ways that games could use to "unlock fast travel" if they really tried. For instance an open world game could have a ground mount and then a flying mount later on, even ON TOP of a (less forgiving) network of portals. But I'm digressing a bit since these are not examples that apply to BG3, specifically.
I love dragon mounts.
Well nothing wrong with that games like WOW MMO have flying mounts and Witcher 3 have at least horses. That said I would be very suprised if Larian suddenly says BG3 will have mounts. +1 for mounts in games, but I doubt mounts is in BG3. Closest you will come to Dragon mounts likely in BG3 is some cutscene with Gityanki riding Dragon mounts.
You could have a Dragon fight in BG3 Act 3 maybe that is realistic. No I dont mean some super huge Dragons necesssary, but example Solasta has a Green Dragon that is not undefeatable.
