Depuis que... present vs passe compose

Question

For the sentence, "I've faced many challenges since I became a parent...", why do you use the passe compose instead of the present tense? E.g., je rencontre de nombreux défis depuis que je suis devenu parent.

Accepted Answer

"I became" a parent - this is a past event that occurred/was completed at the moment of birth of the first child, but clearly 'being a parent' has continued from that time on. It is a point in time (or definite period, even if you include the 'expecting phase' in the description of 'becoming a parent').
The issues of 'being a parent' started in the past and continue through to the present, as described by ' park outings remain among ...' - depuis que an event, with the present tense in French for  the (ongoing) 'have faced challenges" in English.
https://progress.lawlessfrench.com/revision/grammar/how-to-express-ever-since-verb-with-depuis-que?

Answer

Here are two examples to complement Maarten's answer:
Je suis son ami depuis 5 ans. -- I've been his friend for 5 years.On est amis depuis qu'on s'est rencontrés il y a 5 ans. -- We've been friends since we met 5 years ago.
The first sentence talk about a state of friendship that began 5 years ago and continues today. Here, you use depuis with the present tense.
The second sentence is about an event that happened in the past, i.e., when they first ran into each other. That event has passed and isn't extending to the present. In this case you use passé composé.

Answer

I think it is a difference between 1. When what you have been doing since the past event is still going on , eg i have been tired since becoming a parent (ongoing) VS 2. I have been tired many times since becoming a parent (all of those fois ont ete finit now).  The latter you use the past compose because they are all finished now, the further it is still going on