From Proteus, PADS to Ultiboards, Eagle and what not. I have used Altium as well as Diptrace, as well as a whole bunch of other ones for the last 15-20 years, mostly on a professional level. Some you can pick up within a few days, depending on your needs. It takes a long time to set up the whole UI the way you like it, these personal preferences could take hundreds of hours to find. Besides, most people I worked with doesnt like the default UI, colors, and setting even in Altium. Kicad is probably the only cheap/free EDA software I ever used, that I can imagine using. Like you cannot place slot hole for a USB connector It's just not feature complete, which makes it a no go, because it is just a matter of time, when you run into a problem that is not possible to solve. Altium cut down a little bit too much of the features, that actually makes projects impossible. Only get that software, if someone forces you to use it.

And be prepared to create every single component yourself. If you complain, they try to sell you a training. Properties names are coming straight out of the 80s (seriously, nobody is etching PCBs anymore and there is no such thing as antipad) or the source code of a programmer. And call tech support to even get a license working on the PC. Library management is a mess, output generation is a mess, help is nonexistent. I was using it for designing a board, and I'm not even kidding, I had to google how to palce a via on the board (oh, first you have to create a whole library of all the vias that you wish to use, then it is hidden in a sub menu.

Diptrace to altium