What are some ways directors get signed with ad agencies?

I know everyone’s story is different, I’ve just heard some contradictory information and would love some general guidance.

Is making a portfolio of spec commercials and then reaching out to agencies a viable option? Or is it better to put effort into more narrative shorts? Is it more about making something that goes viral online now?

I’ve been making short films and trying my best to get them in front of as many people as possible for my whole adult life, so for narratives I have a decent portfolio. I absolutely love this journey and I’ve been improving drastically with each film, but as most people know here it’s a money pit and very financially unsustainable. Directing ads seems like an absolute dream job for me while pursuing narrative film on the side. I get to flex my creative muscles, keep developing on each project, be on set WAY more than I am now, make pretty good money, expand my network, etc. I can’t stop thinking about it, I’ve been feverishly researching and writing treatments to practice.

I’m totally aware this is a marathon and not a sprint. I have stamina and I’m completely delusional in my ability to make this a career. Im also really aware the industry is in flux right now, and I’m not in a rush to make anything happen immediately. I’m pretty young (24) and have time to develop where I need to, but I just want to put my time and recourses where it’s going to count. I’ve self funded a couple spec commercials in a niche I’m interested in already and would totally do more if it helped me, but if they’re a waste of time and agencies don’t care about them I’d rather make another film and hit the festival circuit again. Money is running out fast

Any advice would be hugely appreciated!!!