I don't know if all do this but they slow your connection down, I have Bitdefender VPN and it slows my 45mps down to half that speed..

I used one for about a year running up to the 2016 election so that I could watch US news and items that were geo-blocked.

Unless you want to get around these blocks or access any sites limited by your ISP (such as torrent sites) it's probably not necessary for home use.

I knew I'd get a straight answer here.

There are places I go that don’t have usable cell data, but I can find a WiFi signal almost anywhere. Highly recommend if you spend a lot of time working on your laptop at Starbucks.

that you send back and forth, so you ISP can't track what you're doing. Also, if you're on public Wi-Fi, your data stream is still encrypted. Finally, you can appear to be in a different geographic location.

I would presume it would be useful during protests , when the cops try to use those imitation cell phone towers.

I use ExpressVPN, myself. App for my phone, and a program for my PC. I think it's $99 a year.

I use a VPN for every WiFi connection. The library, coffee shop, airports, hotels, conference centers... I also use it for my cell phone connections when in certain countries. (S Korea, Belarus, China, Taiwan...)