when GitHub moved to react instead of server rendered pages ie erb/turbolinks/pjax was the start to the end. the pages got slower, rendering became a nightmare

when GitHub moved to react instead of server rendered pages ie erb/turbolinks/pjax was the start to the end. the pages got slower, rendering became a nightmare. then they introduced GitHub actions (half baked) - again very unreliable then they introduced Copilot - again not very reliable it's easy to see why availability has gone down the drain. are they still on the rails monolith ? they speak about it less these days ?