Finding maplibre 'better' was more valid at the time than today, and is also subjective. The creators and maintainers of both libraries have done some great work (and are still doing so).
Back in January 2022, the stable version of leaflet, v1.7.1, was from September 2020, and was affected by some small bugs degrading the user experience. Although the release of following version seemed close, there was no clear schedule for it, and I had concerns about how maintained the library would remain.
As of today, the bug from 2015 where there is some white space between map tiles on fractional zoom levels [0] is still open.
Also, leaflet was a pain to integrate in Svelte Kit framework, because it depended on `window` and-or `document`, not available at server side.
Maplibre, on the other hands, with a feature set roughly equivalent to Leaflet, benefited from much more frequent releases, and seemed more stable across browsers and devices. It was also easier to make it work in Svelte kit.
Would you care to elaborate a little?