At the time the Stipe fight was scheduled, there was no other obvious contender. Jones had just beaten Gane, Ngannou was boxing, Aspinall was coming off an injury TKO loss and scheduled to fight Tybura, and Blaydes had just lost to Pavlovich. Pavlovich was definitely looking sharp and probably would have gotten the next shot, but even his record was mostly filled with lower ranked fighters at the time. Stipe, on the other hand, had only had one loss since 2018, and it was to someone who no longer fought in the UFC - not to mention he held the record for most UFC HW title defenses of all time. So, Stipe/Jones made a lot of sense at the time.
We can talk about how "cherry-picked" we think things are, but - and I know I've said this before, probably in this thread - if Jones had taken the Aspinall fight and beat him easily, everyone would be getting on his case for taking the "easy" fight against the "green" Aspinall, rather than the "challenge" against the "veteran" Stipe. At the end of the day, Jones is out, Aspinall is the champion in the meantime, so Aspinall should be fighting real contenders.