This is like that class study they did where they gave groups of students $5 to start a business and most groups focused myopically on the $5 in terms of what resources it could buy (materials for car wash etc).

The winning group ignored the $5 and sold slots to corporate recruiters to come and speak to their class of almost-graduates and made many times more money than most other groups.

What I'm saying is to use the credits as hosting for projects (like your hackathon entries) to build your skills and give you an edge for the job you want. The credit bonuses on most cloud providers aren't completely analogous to 100k of cash spend anyway because the credits will work on some services but not others.