Broadly, a 3700X will bottleneck a 3080.
The new plaform difference isn't as big as you might think, I did the maths myself a few days ago. A 7600 is broadly as fast as a 5800X3D in a lot of things but not all, faster in other things - but your upgrade path opens up for the future.
A 5800X3D will cost you ~ £250 and you'll get about £80 for your 3700X so ~ £170 total
A 7600 + 32GB 6000 MT/s + a B650 will cost you ~ £430, maybe a bit less, you'd get ~ £150 back for your CPU/RAM/mobo depending on what they are = £280 total
It's an option.