So: I’ll be honest and say I have a fair amount of Stockholm syndrome when it comes to EAGLE: the learning curve was hell, and now I’m through it… I kinda understand the way it is like it is, and actually appreciate a lot of its decisions. Some of its crapness is down to how little it’s changed over the years, but some of it is down to the fact that it’s a CAD tool, not a graphics tool. (My experience of other CAD tools has been similar).
Brief tire-kicking of converting EAGLE-to-other formats was not very impressive, so I’d probably not recommend that. Instead, learn the tool you’re planning to use, make parts in that.
I’d also say now that it’s not like anything else is vastly more user-friendly; if you think that user-friendliness is KiCad or DipTrace’s main selling points… you might be disappointed. The one obvious difference is that EAGLE is unusual in how tightly it couples layout (brd) and schematic capture (sch) (and similarly, how its library bundles up part/package/device). Other tools take the more traditional approach of making them very separate: first, layout a schematic just with symbols, doesn’t matter what the parts are. Then, make a layout, matching symbols to physical parts. This is the traditional, old-fashioned way (and indeed, many companies made tools for only one of the parts - use one schematic capture tool, another layout tool).
As a result of this way of doing things, making your own parts isn’t quite as complex in tools other than EAGLE because the symbols often exist. But I’d point out that making your own libraries/parts is a relatively core skill for using these tools, and makes your life so much easier when you know how.
About the only user-friendly tool I’ve used is Fritzing, and my main feedback on it is that Friends Don’t Let Friends Fritzing. I’ve made boards from it, but its parts support is limited to say the least; it’s friendly, and it’s kinda useless.
I am happy to answer or attempt to answer any questions about EAGLE. The learning curve is steep, and it’s only right to share knowledge.