Trump is interested in votes and money. Bitcoin can bring both because it's not hard to be pro-crypto following pretty harsh measures of the Biden administration, and since Bitcoin is money, you can (and that's what he's doing) fundraise more for your presidential campaign from Bitcoin enthusiasts.
I don't support Trump as a politician, his views are far from my own. But, more importantly, I truly don't believe that Trump is sincere with his pro-Bitcoin stance, considering that he was consistently anti-Bitcoin for all those years before, and it's a very convenient time to change your policy.