So, alternative take. If you have a home PC would you be better upgrading it and getting a cheaper laptop for more basic use?
Basically do you really need a mobile work horse? If you're doing video work then you may be better with a graphics card or CPU upgrade £ for £. Do you really want to be editing videos on your sofa or in bed? It doesn't seem like the easiest or most productive way to work in that particular use.
You can also stream any game from your PC to a low power laptop (or other devices) using Steam or other streaming tech. The pc can be on but with the sound and screen off, while you're elsewhere streaming a game.
So maybe a PC upgrade and a shared basic laptop for video and internet would be enough? The only downside is if you genuinely think you would want to do full on video work on the go - out of the home or abroad for example. Then it makes more sense. But a powerful laptop around the house when you have a PC that does the same seems a bit pointless. It also means work drifts away into the rest of your home, whereas now when you're not at your PC you're not working.
But if this is more talking yourself into buying an expensive toy, there may be better toys to be had for far less. Like a steam deck - under £400 for a decent machine, play games anywhere in the home (on the device or streaming to the device), get a dock and plug it in to your telly.
Edit: other way to think of it: do you really need the laptop? What could you spend that money on instead? There is an opportunity cost if you spend that money or take on debt for something you don't really need. You could save that £42 a month and treat yourself to something else in 6 months or a year.