'Niche' pokemon in the metagame

I made a post on here sharing a mega beedrill team I made and I have been playing it ostensibly sense then. Ive kinda gotten on that high of making a team "work" with niche-I won't say bad because... well that's mean- pokemon. Ive tried Pikachu, lycanroc day form, and gliscor and the one thing they all have in common is the supporting cast is all filled with meta juggernaughts. It made really question if I am making a pokemon work through excellent team building or if I was just slapping it on an already good team that wouldn't suffer explicitly from its addition. For example on the mega beedrill team I always run beedrill with garchomp, he is never not coming to a fight and usually garchomp carries while beedrill may get a surprise ko on some pokemon. On teams where every one of their pokemon they bring resists poison or bug I have to hope garchomp can ko every single one of them. This is probably a flaw in my team building and not letting beedrill be on a team where it shines, but there not much to the contrary of what to do. What im saying and what I probably should've made a thesis statement about at the beginning is this; How can you make a niche pokemon shine on its own, in a team where it is the star player. Share your thoughts I guess.