WiFi 6 router AND modem for fibre?

[#1]

I have fibre unlimited and use TP link VR2600 modem/router as the supplied one is rubbish. But nowadays I have lots of wireless devices connected (16 in total) and I get frequent dropouts. My line test came back as good. I have changed channels etc.
I want the latest wifi6 router but the question I have is, do I need a modem as well? Plusnet support suggest I don't, that fibre doesn't need a modem......is that true?
Can I just get an Asus wifi6 router and be done with it ...it should work?

[#2]

You’ll need a modem, either separate or built in.
Do you have any devices that actually have Wi-Fi 6 or are you just trying to future proof?
A mesh system might be better.

[#3]

Future proofing for 1
But I was led to believe that my modem/router might be struggling with 16 wireless devices. Not something a mesh would solve?

My concern that it wasn't my modem/router was because my TV is wired to my router and Netflix on my TV goes down when my internet dies on my wireless devices.... Which is weird right? Wired shouldn't be effected...

[#4]

Looking at the specs of your current router I wouldn't have thought that 16 devices would be any issue, unless it has developed a fault itself.

I would start by looking at your line first as it sounds like your line might be dropping.
Next time it happens have a look at the system log and see what it reports in the router under "Advanced > System Tools > System Log page"

Also check there is no noise your phone line with a quiet line test, needs to be with a corded line:
Once you have your telephone connected to the BT test socket dial 17070. You will reach BT's line test facility.
Choose option 2 from the menu presented - "Quiet Line Test".
If your telephone has the option, put it on mute. You should hear nothing through the handset.