Any time I use the internet, regardless of what connection, I basically always keep it on. I may swap servers in some most likely ineffective way of keeping myself safer from tracking, but otherwise it normally stays on. Only other exception is when flarpak isn't allowing updates to come through.

If your vpn uses Wireguard then it should be a minimal difference. You can always split tunnel if you need full speed but wireguard is plenty fast in my experience.

I use airvpn 24/7 and get full speeds even when I had gigabit fibre. Was always limited by a single server connection for a service capping out whether on vpn or not

That's probably pointless. You should only use it for piracy, bypassing content filters, regional blocking, and things like that. Otherwise you're just wasting money/hurting your internet speed for zero benefit.

A VPN only offers marginal protection from tracking, since it only hides your IP address. Most tracking happens in the browser, via cookies and fingerprinting techniques. The only reliable way to protect yourself against that is Tor, and you should not use Tor with a VPN.

I like Mullvad and I am a happy customer, but this misleading advertising is kind of a bad look IMO. It's good to raise awareness of this serious issue, but they're clearly trying to profit off of consumers who don't understand the product they're selling.

Never slow for me with Mullvad.