Many people don't have reason to prefer a CRT, and that's fine too. Lots of non-CRT options out there to use.
The replacement parts have a footprint, and a newer monitor might use so much less power in operation that it’s more efficient to make and use it than to continue to use the older CRT.
I really wish there were an easy way to work out if this was where the ‘efficiency crossover happens in X years of use’ point was. For example, I have a perfectly usable Thunderbolt 1 [edit: Thunderbolt 1 dock] that meets my needs. But it uses 5-10W of power more than a new Thunderbolt 3 or 4 one would. Should I continue to use it or switch to a newer one?
If your usage isn't continuous (which it probably isn't), that'll reduce your electricity cost and extend your break-even point even further; if electricity costs more in your region, it'll shorten it (average EU energy prices are around double that of the US IIRC, and some countries are much higher). But it's still going to take a while to break even if the efficiency improvements you're considering are in the 5-10W ballpark; that's not all that much power in the grand scheme of things.
Whether it's better to buy a new monitor or run a rescued CRT isn't merely a financial calculation based on manufacturing and operating costs and emissions. For retro gamers and CRT fans, LCDs are usually not a replacement for CRTs in gaming and media consumption, unless you use emulators and CRT shaders, or expensive scaler boxes which apply simulated CRT effects to real consoles' video outputs. And for all but the most obsessed CRT fans, CRTs are not a replacement for modern high-resolution LCD monitors for web browsing and office tasks (the sharpness, lack of flicker, and not having to juggle VGA DACs is a major advantage).
In practice the ideal display is a complex calculation based on scan rate (SDTVs can't show high-resolution signals and VGA monitors usually can't show television signals), display size (>40" LCDs are easier to get and move around than >30" CRTs), cost and reliability. Some people have multiple CRTs they maintain and use for different purposes (alongside LCDs), but I only have the space and energy for one VGA monitor (though I envy those with entire game rooms filled with vintage particle accelerator displays).