I carried a BIG camera rig for over 30 years. Made a lot of pictures at some really great locations. Sold a bunch and made a lot more memories. That said, about 5 years ago I switched to m4/3 and have noticed no appreciable decrease in image quality or impact on editorial acceptance. If I did billboards or fashion layouts, I'd still be using full-frame. Since I don't, the only real impact has been to my back - less pain - and my carry-on size - much smaller, lighter and more compact. When I was 30, carrying a 35mm, several lenses and related gear up a 20k+ peak was a pain but necessary. Nowadays, with the equipment we have, I'd never do that.
For travel photography, I would never go back to BIG gear.