You just gotta make sure you get the right kit for your printer, as most have a chip in them that acts as a page counter. You typically have to replace the chip when you refill.
Some models like mine require you to melt a hole into the cartridge, there's no external access to the toner tank. Make sure to do your research and don't buy the cheapest kit you find. The quality of the toner does matter and will greatly affect print quality.
They basically all (but I will leave room for the possibility of a non-evil printer vendor) suck in a myriad of different ways from poor quality, to all the various dark/anti-patterns in both the original sale and the subsequent consumable sales.
If it is low and the page is faint that's fine for my home printing. I don't need HP to tell me to replace the cartridge. Caveat to that is that it is "only" black and white but then I've never needed to print colour.
They also support Linux so all the computers in the house work fine with it.
Over a decade in on my B&W Brother HL-something-or-other-im-away-from-the-desk. No shenanigans, just good printing.
You can reset it with some faintly annoying incantations, and I'd suggest doing so until you notice actual print quality issues. Especially on black.
The logic is... reasonably sound from a print quality perspective. "We know the cartridge can print XXXX pages of reasonable coverage without any fading/dropouts/etc. If the user replaces it at that point, they will never have any print issues." If your goal is "flawless printing," it's a reasonable enough path. It's just not particularly cost effective for the end user. It is, however, cheaper and more profitable than actual toner level sensor/mixing device/etc.
But, yes, there's a hidden menu to reset the toner counter on Brother, and in my experience, there's at least another 50% of rated capacity pages lurking in the cartridges unless you print very toner-heavy pages.
But you may also get a little toner on you or the floor, so beware.
It's exceedingly unreasonable for something like a small office printer to have people constantly reprinting things because the toner is almost, but not entirely out, so please remove the cartridge, shake it gently, etc. Remember, the paper you're spending on partial prints and the toner you're applying isn't free either, and people's time isn't, either. Neither is the carpet cleaning of the toner spot in front of the printer from people trying to stretch it.
I'll reset the counter on mine, give it a shake, and run it until I see any impact on printing, but as soon as I notice any streaking, I just replace the cartridge. It's not worth the hassle to fight for 100 pages of toner to me at this point in my life.
I know that Brother includes a starter cartridge that usually includes less than even a standard size replacement. They have high yield cartridges and I have only ever seen the bigger size in third party replacements.
The model I have is the 2270dw which was purchased years and years ago. The bigger replacements are rated at 2600 pages and standard are 1200. The drum unit can do up to 12000 and I don't think we've replaced that yet. I did reset it a couple times to get past the toner warning, it continued printing well into faded pages without issue. All it took was holding a button on the front while turning it on and then pressing the same button a specific number of times after initializing. The third party replacements are priced reasonably well in my opinion.
Annoying is sleep mode that cannot be changed. Printer won't turn on when I send print task to it. I have to turn on printer manually every time before print.
It's not like printer tech has improved much in recent years. I suspect a lot of what they're charging me for is R&D into how to prevent customers from using 3rd-party cartridges and a big profit hike to congratulate themselves for doing so successfully.
Do you think that applies to the Neverstop models? They have an internal toner tank that refills with syringes, so this kind of nonsense isn't really possible.
My HP LaserJet Pro 400 series m401n will keep printing even as the print quality fades, presumably due to actually low toner.
(This is running with CUPS and open source PCL drivers on the client, talking TCP to network passthrough to printer's USB, no HP-written software used off-printer.)