@DinoNuggetsRUs when you say you're going to have another go at the photos, does that mean you took the originals?
However you take the photos, they should be on a decent grade camera or phone, at the highest quality setting available. If you're on an iphone, try using the 0.5x lens as well as the 1x lens to see if it helps.
If the photo looks a bit dark, tap the screen on a darker part of the room and it should brighten up the whole image.
But yes, photograph the property during the lightest part of the day. If that means taking pictures of the front rooms at a different time of day from the back rooms, do that.
If you're not in a hurry to sell, I'd perhaps even wait until Spring hits a bit more and the UK in general is less grey.
Declutter as much as possible, clearing off your dressing table, under the sofa and kitchen cupboards, moving the extra shelves/shoe racks/trolley in the kitchen, etc. It's fine to leave some stuff and some personality, but too much stuff can make it look like you've not got enough space.
I remember my poor car had loads of stuff in it when I was selling an old property as I was just trying to keep it as tidy as possible.
I'd spread your kitchen bits on the worktop out a bit. It's great that you've got a long worktop, but to have the microwave, knives, bread bin, air fryer and kettle all in one corner makes it feel more cluttered than it is.
I can also see doggo's floofy tail in your living room picture (in the kitchen) and your cat in the bedroom, so perhaps make sure they're out of the way.
As a PP has said, the multiple rugs looks like it's either too cold, or hiding a damaged floor (I speak from experience on that one!).
Finally, I presume that's a starlink in your garden? Does this mean the regular internet is rubbish? Given a lot of people WFH now, internet speed is super important.