LazyRouteFilter doesn't handle priority

confirm that priority does not taken into account

It does not. I just had to work around this in Page Manager by making the route filter non-lazy.

- { name: route_filter }
is for lazy route filters (which is a Drupalism), and currently does not support priority

- { name: non_lazy_route_filter, priority: -1024 }
is for regular route filters, and works fine.

See also #2647590: Add support for priority to lazy route enhancers

#2472337: Provide a lazy alternative to service collectors which just detects service IDs would solve that

#2883680: Force all route filters and route enhancers to be non-lazy is a concrete issue to resolve that particular problem.

#2883680: Force all route filters and route enhancers to be non-lazy fixed this.