Is it better to upgrade my current PC or build a new one?

Hey everyone! I'm relatively new to PC building—my experience is mostly from playing PC Building Simulator for a few months. I love my current setup, which was put together by a family member around 2019, but it hasn't been upgraded since then, and I'm starting to notice some bottlenecking issues. Apart from updating my GPU drivers, there's not much I can do with it. I'm trying to stick to a budget of $800.

Here's what I'm considering: should I upgrade my existing build or go for a completely new setup and pass this one down to my younger cousin? I'm also planning to start offering professional 3D art services, which adds another layer to my decision-making process. Here are my current specs:

- CPU: AMD Ryzen 5 1600 – 6 cores / 12 threads, running around 3.7 GHz
- RAM: 16 GB DDR4 (running at 1467 MHz)
- SSD: D_BLACK SN770 1 TB NVMe
- GPU: NVIDIA GeForce GTX 1070 Ti – 8 GB
- MOB: ASRock Fatal1ty AB350 Gaming-ITX/ac
- PSU: EVGA SuperNOVA 650 G3, 650 W

I also have an extra 1TB HDD, but I'm unsure about the model.