Comment by ivan_gammel

Some inspiration came from C++, Modula-3, CLU etc. (note, inspiration, not validation of the idea)

They exist since v1, which had very different philosophy than Java of 2010s-2020s. 1990s were an interesting time in language design and software engineering. People started reflecting on the previous experiences of building software and trying to figure out how to build better, faster, with higher quality. At that time checked exceptions were untested idea: it felt wrong not to have them based on previous experience with exceptions in C++ codebases, but there were no serious arguments against them.