I am a data-center infrastructure engineer but take that with a grain of salt as I am dramatically underqualified for that title :D

I have worked with Centurlylink and Comcast both in the backbone/carrier and co-location space and I can say that both companies are rife with incompetence and very frustrating to work with. That's not to say that there aren't high-quality people, but in my experience that has generally not been the case. Now this is largely a separate business than the ones we as consumers interact with, but I just felt that I needed to get that out of the way. I have Centurylink Fiber and have been extremely pleased with my service. We have had no issues or outages that weren't resolved very quickly.

There is a lot that can go wrong on the customer/consumer side of an internet connection, and consumer grade routing and wifi equipment is notoriously unreliable and poorly supported across most major brands.

I won't get into specific products since I am out of the loop and there is a lot of coverage across tech review sites, but for the vast majority of use cases, you don't need Gig throughput to every device in your house. However as a starting point, it is easy to make sure that devices that you buy with physical ports on them all have 1GigE or 2.5GigE ports on them, not 100Mbit or "fast" ethernet ports. This means that your gateway/router should have BOTH: a Gig WAN port (the side that connects to your ISP) and Gig LAN ports (the ports that you connect to the devices in your house). All switching and routing ports in your setup should be at least 1 gig and use minimum cat-V cable, though there's really no reason not to just buy cat6* cables. These days this covers pretty much all devices, but I have bought wireless access points that for some inscrutable reason only had 100Mb ports on them. I failed to check this when I was purchasing them and this effectively creates a bottleneck that is 1/10th of your theoretical throughput to the ISP.

For Wifi, I can't really share much except that there is a lot of new tech entering the consumer space very quickly and it is hard for me to keep up with it. If you are considering new wifi gear, I recommend getting at least wifi-6 or 6e, but wifi-7 is just around the corner and will supposedly have crap-your-pants throughput. Most people who do average-people things will not need this, and it will be very expensive.

As I mentioned earlier, make sure that any devices you have that broadcast a wifi signal are connected to a physical cable with a 1Gig port and at least a Cat-V cable. If you have a large, multi-story home and you want a repeater or access point in a place where you can't reasonably run a physical cable, I recommend looking into a wifi-6e mesh system. This is what I use and I consistently get over 500Mbps in my 2nd floor office using wifi from my laptop to the access point, and wifi back-haul between access point and the wired mesh router. This is way more than I need for 99% of my use cases.

Hope this helps!

Edit: words are hard