Hi Wrath, I have been struggling with this endless dilemma on midlane for years and I am currently stuck around plat 3 - plat 2.
I'd say I would introduce myself as a player without much technical talents. Few years ago, I was pretty much hardstuck silver elo and then I learned some macro tips and applied them with meta champions to climb.
Since I didn't have a champion that I actually "mained", I do have a large champion pool on midlane. But I have realized whenever I played aggressive champions, I am just unable to snowball off of picking up kills or roaming. So I usually play passive champs like Galio, Viktor, Vlad, etc.
I feel like the current meta of midlaners are basically jgler's secondary support so they can push lane first and help out jg and other lanes. Whenever I get to have lane prio, lets say, I play Galio and pushed out lane to help bot lane. Then our bot lane gets fed and our jg takes enemy bot camps. At the same time, enemy mid lane takes tower gold and farm.
Later on in the game, since I played around my teammates and helped them while enemy midlaner farmed for themselves, I am little bit behind on xp and farm. Then a fight happens for an objective and our botlane dies to well-fed enemy midlaner with their bounty gold they earned due to my roaming early game. Then all the enemies takes the lead in the game with all those bounty golds.
Sorry for asking such a long question, but I am just clueless of how to win games through roaming or just in general. Games where I don't even get the lane prio, I just tend to be just non-existent in the games. I try my best to farm safely, but I would just never get the situation of taking the lead of the game back.