It is worth it if you don't take a loan and dump all your money into it as a full time job. If you have a full time job and the cash to spend just do this as a hobby to make extra cash it is still worth it. The huge miners is what hurts the little guys anyways.
I didn't take a loan, but I moved almost 2 years ago so I could afford to make mining my "full time job".
It's been worth it and still is at this point - for me.
Your details and preferences may differ.
GPUs don't "go obsolete" in 3 years, even in mining usage - the HD 7870/7950/7970 from *over 5* years ago are still effective profitable miners, and the R9 290 from about 4 years back or so is STILL one of the top Ethereum miners on hashrate (only surpassed reliably by the GTX 1070, GTX 1080ti, Titans of the Pascal generation, Titan V, matched by the R9 390/390x and SOMETIMES topped by Fury and Vega cards).
If your electric cost for a GPU rig is 1/3'd of your gross income from that rig, you have high priced electric by mining standards.