There is a tremendous amount of benefits with Amateur Radio vs. GMRS. First, lets just talk about voice.
On GMRS simplex, the absolute very best you can expect from a perfect setup, is going to be about 70 miles. Likely less. That would be mobile or base.
With Amateur Radio VHF and UHF, the power limits are 1500 watts with no radiated power restrictions. That means with a little elevation, you are talking coast to coast on the higher portions of VHF and the lower portions of UHF. On the lower portions of VHF, you can talk to Europe, Mediterranean, Northern Africa, etc. Even in my mobile, I can talk to NY from Virginia on VHF simplex.
With things other than voice... there is no limit to what you can do beyond no encryption. If you can dream it, you can do it on amateur radio. There is APRS, which provides transceiver location services. There FLDigi which is used for texting and simple messaging. There is WinLink which is a 100% radio-based email service that allows you to email other operators as well as people on the public internet. And much, much more.
The benefit of HF and MF is, the ease of global comms as you drop in frequency. I was driving around in my Jeep today on an HF frequency that Tech license holders have access to. I talked to people in 3 different countries on 2 different continents with a simple 100 watt mobile radio and a whip antenna. It's really a lot of fun.
As far as a base station goes, I don't use mobile radios for base a station. I have base station radios that I use for VHF, and a VHF/UHF repeater. I talk on VHF on the base for several hours a week, sitting in my executive desk chair.
As far as the quality of conversation... I can't really say much about that. I would assume there are plenty of people to talk to without getting into religion, politics, etc. I avoid them like the plague.
With regard to if it's worth it... that is a personal choice that each person needs to decide for themselves. I think it is. I held my Tech license for 17+ years before I got my General and had a great time. I also think the GMRS and FRS are great radio service and fill a nice niche.
