A smaller platform is a real trade-off, not a reason to skip it
Bluesky's audience is smaller than the largest established platforms, which is a genuine trade-off, not a reason to dismiss it outright. A smaller platform in an earlier stage of its growth can be exactly where being present early pays off later, the same way early presence on any platform that later grew large did for the accounts that got there first.
The real cost of adding a platform is upkeep, not setup
Connecting one more channel is a small, one-time task. Keeping it active, posting there consistently rather than once, is the real ongoing cost. Be honest about whether that capacity exists before adding a fifth or sixth platform to manage.
Cross-posting is a reasonable way to start
For a platform still building an audience, cross-posting content already made for another platform is a reasonable low-effort way to maintain a presence without a large extra time investment. Fully platform-native content is worth reserving for whichever platform is already a genuine priority.