Everyone likes a freebie, and there are certainly hundreds of free VPN services out there. But if you want a great streaming experience, you’re better off choosing a premium option. Free services won’t give you access to many streaming platforms, are usually very slow (so you can expect buffering) and/or impose data caps. Free VPN providers who have premium options also usually restrict what features you can actually use without dropping your card details. This is the case with ProtonVPN's free service.
Generally, they’re not great to use and are only suited towards simple tasks. Plus, a lot of these services are spammy. What's more, you could always just opt for a super cheap provider like Surfshark if you’re concerned about pricing.