Based on your original post, it’s likely that Google already has your phone number on file—a clear privacy red flag unless you used a burner number. Revolut is a great start, but if you’re serious about privacy, opt to purchase YouTube premium exclusively either through the App Store or via Google Play Store gift cards.
Equally important: never authenticate your Google account on any Android-based hardware, including smartphones, Android TV smart TVs, Chromecast units, Google TV Streamer devices or other streaming devices. Each login lets Google harvest nearby network SSIDs and triangulate your location via passive telemetry.
Unless your ISP already places you behind a CG-NAT (which can obscure your general geo-location and help you blend in with other users) always access YouTube and other streaming services through a trusted VPN or residential proxy to mask both your endpoint address and network footprint.
Skipping any single step would greatly reduce your privacy.
All things considered, unless you specifically need YouTube Premium or an account for some other reason, your best bet for protecting your privacy is to use a privacy-focused browser with an ad blocker (ideally routed through your VPN or proxy) all while logged out or to use a YouTube privacy frontend. Combine either of these approaches with RSS feeds for your subscriptions so you can stay up to date without compromising your anonymity.