IMO, Jaeger is easier to setup/manage and has a better interface than Grafana/Tempo. It's easy to add Jaeger to your local dev stack so you can have tracing while developing.
FWIW I now use Tempo because I have everything else in Grafana (Prometheus, Loki), but I do miss using Jaeger.
Jaeger can use multiple backends for storage, including Tempo, so it's not an either/or situation.
I'm fairly sure there was an official Grafana-provided Jaeger gRPC plugin for Tempo, but can't easily find it, only this one: https://github.com/flitnetics/jaeger-tempo