Gee... a vendor trying to up-sell you to a more expensive product you don't really need...
Who'd a thunk it?
That said now I'm going to offer something sort of in their defense.
The first thing is that, if you read the "fine print", home Internet access is
ALWAYS sold as "
up to xxx mbps".
This means that they are
NOT promising that you will always get that speed.
In fact it means that they aren't promising that you'll always get anything even close to that speed.
It's more like "if you're really lucky then sometimes you'll get somewhere close to that speed".
(The reality is that, depending on the situation, you may even occasionally get
BETTER speed... but it will vary... and don't count on it.)
This will depend on your modem, and how your neighborhood is wired, and even how your
STATE is wired, and on what's playing on Netflix tonight.
(And one ISP may be better than another in your neighborhood or area... the details are really complicated... )
The second things it that... now listen carefully...
THE INTERNET ITSELF IS NOT DESIGNED TO PROVIDE ABSOLUTELY SECOND-TO-SECOND CONTINUOUS SERVICE.
That's a nice way of saying that,
no matter how fast your service is, or what you pay for it, it may "drop" for a second or two, or longer, every now and then.
There are almost always quite a few routers, links, and transfer points between whatever server you're streaming from and your streaming box or computer.
And any one of them may occasionally drop for a second, or longer, or transfer your traffic to a different route, or do a system reset.
And, of course, the server itself may "hiccough", or "glitch", or whatever, and your cable company may be "doing service" in your neighborhood.
(It's also worth mentioning that, by and large, "5g wireless service" is
MORE prone to momentary outages than wire... that's reality... live with it.)
It's up to your streaming box, or TV, or platform, or whatever, to cover for this (that's what "buffering" is for)...
But that may not work perfectly... or sufficiently...
The upshot of all this is this...
Something like 100 mbps service should be easily able to deliver one or two 4k streams.
BUT you
WILL usually be less likely to experience noticeable drops and losses the faster your service is.
With faster service, you
may be getting a faster router, and those buffers will refill faster, and other parts of the system may recover or switch over faster.
So there is some truth to the idea that having faster service, far faster than you should theoretically need,
MAY mean that you experience fewer problems.
This may not play out for you, in your neighborhood, and with your requirements...
But it's also not entirely unreasonable to suggest that, at least sometimes, you will benefit from having far faster service than you "actually need".
Now, to be fair, from my experience, they guys at your local cable store may just be inexperienced clods, blindly hoping to upsell you to a more expensive option...
But it's also possible that they may know something you don't (even if it's just that they get fewer complaints from people in your area with the more expensive service).
I recall one of my last trips to the Internet service provider who spent a few minutes lying to my face about what I needed versus what I didn’t need all in an effort to get me to pay more per month or something that wasn’t necessary… How could an Internet service provider do something like that? I have no idea!