low key going ROH / NJPW / Dragongate / DGUSA is 100x better way to learn the business and sharpen your teeth than TNA, easily.
True, though the style is absolute hell on the body.
If you're established and older, though, it's almost better to break into New Japan and work major tours and some indies than take your chances with WWE's capricious booking. WWE has the higher upside, being the much bigger company (although that's being mitigated by disappearing PPV and video game residuals and declining house show checks), but being a top guy in New Japan just might be the surest bet to make the best living possible off of wrestling.