The largest benefit to a larger internet connection, say above 100mbps, is to upload more money from your wallet into the ISP.
Most applications do not use a lot of bandwidth. Thing like 4k netflix maybe use 25mbps. Online games use less than 1mbps. Web browsing is in effect download lots of tiny little files but because of the overhead related to web pages it does not use much.
The thing that can use a lot of bandwidth is very large file downloads. It will download say a large game that is say 20gbytes in much less time. It all depends on how many times per month you do this. Is saving say 5 minutes of download time a month worth the extra charge.
Now there might be some other not as common uses. Say someone who works from home and needs to upload and download file to a common cloud storage used by other workers. Someone who would need to compile large amounts of software programs or maybe working on video rendering files.
It all depends on how much the cost difference is between the plans and if you feel you are getting value for it. ATT for example charge $55 for 300mbbps, $80 for 1gbit and $180 for 5 gbit. I don't know if att still bundles HBO with the 1gbit and faster plans.
There is really no way to say which ISP is available at your house. You are going to be very lucky to even have 1 fiber provider. You might also have 1 provider over coax cable and then there is always the slow DSL on phone lines. What you can get can vary greatly between different parts of a city.
Best way to see what is really available might be to talk to some of your neighbors.
VPN is mostly used to bypass some restriction, say you want to watch netflix in another country or you are doing something illegal and attempt to hide you home IP address. There are also some cases a ISP has poor connectivity to some other ISP and a VPN can perform better but most times VPN is slower because of all the overhead.
Since all internet traffic is now encrypted and you can even choose to use encrypted DNS, vpn is not needed to prevent interception of data as much.