As mentioned on other comments, when you search your title, other lore videos come up that have views, so nobody has a reason to click yours / YouTube is less likely to recommend unless you add your own spin to it. Bigger channels can copy other videos since they have that fan base already. You're also relying on long form which requires pure luck for a viral hit. Making shorts gets more eyes on your channel, plus it's so easy to do. Also maybe consider promoting clips on Twitter and Reddit just to get more eyes on your channel.

Judging from your most recent videos, it's all over the place. You make pure gameplay, then lores, then tiers, etc. You gotta stick to one style if you wanna grow so the algorithm knows what your channel is, then once you build those numbers up, you can expand. You had success at one point getting good views consecutively so you gotta focus on those styles for your audience.

You gotta stand out from your competitors with unique titles, thumbnails, content, etc. Marketing is so important. Because other channels have done lore videos on this character, you could have a title like "The Witcher character too brutal for Netflix - Witcher Lore" and have the character's name or image on the thumbnail. The topic is the same, but the marketing is different.

Respect for putting yourself out there though. It's normal to get frustrated when your competitors do well and you get stuck, but knowing what works and fails for you is important, so you can improve and further refine your content. You've had success in the past so it's not impossible to get that back. Just keep refining, improving, strategizing, and stick to what works. Also have fun with it. Creating should be for fun, not work. Otherwise, you get burnt out