Altium is probably the industry standard, though there are several high-end competitors (OrCAD for example). Similar to how Solidworks is usually considered the standard for CAD, but there are lots of competitors in the $2k/annum range. EAGLE was/is certainly used in production in many places, but it gained traction because it was competent and their free tier was good enough for almost all hobbyist work.
EAGLE was barely maintained for years, until Autodesk bought it and started making a lot of improvements, but the changes were often buggy and broke existing workflows. They also changed the pricing structure and many pro customers were unhappy about that too. But while a lot of people grouched about it, it's not like EAGLE was ever been a shining beacon of good UX.
It seems like EAGLE is being merged into Fusion 360 instead, so you have a unified electronics/CAD environment.
Altium is resting on their laurels though, whereas KiCad is actually picking up velocity and adoption. One of the biggest things the EDA industry lacks (and altium doesn't even support until you pay them big money) is meaningful automation / version control.
Altium has this, but coming from the software side of things, holy hell is it poorly implemented and clunky.
EAGLE was barely maintained for years, until Autodesk bought it and started making a lot of improvements, but the changes were often buggy and broke existing workflows. They also changed the pricing structure and many pro customers were unhappy about that too. But while a lot of people grouched about it, it's not like EAGLE was ever been a shining beacon of good UX.
It seems like EAGLE is being merged into Fusion 360 instead, so you have a unified electronics/CAD environment.