Today even office use desktops we spec with 8GB of RAM. If you have 4GB of RAM. Half of it already gone to the OS . Antivirus another 300MB. You left with 1GB+ of RAM for browser + microsoft office ? Once Windows Update run at the background , the system will lag like no tomorrow.

For Dell prebuilts , the proprietary stuffs are:
1. Motherboard -> non standard form factor.
2. Power supppy -> non standard , especially the connectors and form factor. Not ATX , SFX or TFX
3. CPU cooler -> the holes are not the same as AM4 or Intel LGA spacing.
4. Casing - the power on button , reset connectors to the motherboard are proprietary.

The above stuff you have to buy replacements parts from Dell. Usually is refurbished only. Or used online from 3rd party seller.

Dell support is very good. I agree. Because even if u live in the jungles of Borneo , they will do onsite support warranty service for u. But hopefully u get 3 yrs warranty , usually stuffs can fail around 1 1/2 years if u are unlucky.

RX6500XT is gonna be trash for sure. 64 bit memory bus is a red flag already. It will be heavily starved of memory bandwidth.
Even if in non-gaming workload , RX6500 XT does not support AV1 decode which is what Youtube videos are currently moving to. So the CPU has to do it which is ridiculous , seeing all RTX 3000 series have hardware AV1 decode support.