I have talked about this in threads the past, many US homes are paying for speeds that they would hardly ever actually utilize.
Many ISPs try to upsell these speeds, getting their customers to pay an extra $20, $30, or even more a month for Gigabit speeds, but for many, Gigabit speeds is overkill. Even 100Mbps speeds is overkill for some.
For perspective, you can stream over 50 different 4K HDR Netflix streams simultaneously with Gigabit internet.
I personally know people that are paying for Gigabit speeds, and they only use their internet for streaming apps and things like Facebook.
All that said, there are definitely use cases for faster speeds, but I would bet in most cases, the user already knows that they could see some real benefits from increasing their ISP speeds.
If you are currently fine with your internet and you don't have problems, why spend the extra money?
I have Xfinity home internet,
If you are using a Cable ISP, then there could be some benefits from increasing your speeds, maybe not with the download speeds, but with the upload speeds.
Most Cable ISPs have asymmetric download and upload speeds, meaning that the upload speed is sometimes a tiny fraction of the download speed.
Comcast is one of the worse, only have 5Mbps upload speeds on a lot of their Internet Service tiers. If you need a decent upload speed, you often have to pay for download speeds that you don't need.
Me for example, I need more upload speed than what Comcast currently offers, but I am stuck with them in my new home. My family could totally get by on 200Mbps download speed, probably less, but I am forced to pay for the Gigabit speed tier to get the 35Mbps upload speed.