journeyman is not someone who would ever become a champion. usually someone with a lot of miles who was never that great or highly ranked but does have some abilities (usually, just being tough and being able to endure beatings lol).
a gatekeeper is also not someone who is on the way to being a champ, but someone who was never quite good enough to crack the top but stuck around near it forever and forms a barrier to other fighters from reaching the top, or a former champ/top fighter who declined out of contention but also hangs around near the top being a challenging fight for up and comers.