We have to go back to 2017 first. I passed my first MS exam then, It was part of my development plan at the project company I worked for. Telling a junior to take a MS exam saves a lot of time as there is no need to allocate senior dev. time for mentoring or evaluation as usually, you can prepare for the exams on your own from books and other online sources.
In 2018 I changed jobs to a company that was an MS partner, I think they liked that I have an exam, I also dazzled them with that custom Power BI visual with the fish tank.
They put it in my contract to take two exams in my probation period.
My last exam before this was the PL-300 in 2019. That was not planned; I just won a voucher at one of the Power BI kahoot games that Just Blindbaek used to host.
Taking these exams are only complimenting real-world experience. It's also true the other way around, you can do a lot of things in Fabric without understanding what is a parquet file or delta format, but you should not go far into development before understanding the basic concepts and having an overall view of Fabric.
I recommend watching every video from Will Needham and joining his Fabric Dojo community and doing the MS Learn path . Nikola Ilic also has great videos about exam topics.
I think the benefit of taking an exam is showing commitment and a serious interest in a topic.
I plan to reach out to other people in Hungary who are trying to implement Fabric and this badge gives me some credibility.
Btw. they changed the skills measured of the exam from middle of November.
https://learn.microsoft.com/en-us/credentials/certifications/resources/study-guides/dp-600#skills-measured-as-of-november-15-2024
I recommend the Szirtes test center for you consideration.