Dreamingr0b0ts is a fantastic house/trance YouTube channel with a mere 123 subscribers. (It may not technically be synthwave, but it's synthwave-adjacent)
Some of the very oldest videos are a bit rough around the edges, but they quickly improve in quality. I like this channel because it has more of an old-school vibe than most synthwave; it reminds me a lot of early-2000s electronica, back in the days of Armin van Buuren. Vocals are present more often than not, and the vibe is more "dance" than "chillax." Great music to stay awake during a long road trip, or to stay motivated during a big house clean-up. A lot of synthwave videos rehash the same songs over and over, but as far as I can tell these are quite fresh.
Check out their "The Daily Dose" series, each of which are albums of about 20 minutes each.
I'll admit, I was on autopilot when making the first round of posts to populate this community and included this channel without thinking it through completely. As you've observed it's an EDM channel, not synthwave. Despite my mistake I'm leaving the post up because 1) there's a good amount of overlap between fans of synthwave and fans of EDM, and 2) the DJ seems to be trying hard to make good videos despite his lack of audience, and I want to direct more folks to his channel.
No worries man, I wasn't complaining at all. I really liked the episode I listened to so I subbed and will check out more. I almost did the same thing earlier today listening to Dayseeker. I started posting it but realized it's not Synthwave lol.