There are some cases that I've heard where a diagnosis may hurt you professionally, such as in the US military, but most jobs do not require a disclosure due to the American Disabilities act. Maybe check with your country and field of work. You also don't have to tell anyone you don't want to, and you probably already face as much discrimination as you would if you were diagnosed (people ridicule autistic traits, not the diagnosis).
In terms of benefits, I think that disclosures actually have the biggest benefits. Some of this means admitting it to myself, such as realizing I'm not just being overly sensitive (what I was told growing up), and that I'm not as good at understanding people as I might pretend that I am. You can also tell your friends/family with more confidence (ex: my mom is more understanding of me going in my room to take a break from family gatherings), and also ask for workplace accommodations (change of lighting for migraines, less expected socializing, etc). While much of this can also be done without a professional diagnosis, one thing you need a diagnosis for is applying for disability. This doesn't apply to me, and it probably doesn't to you since you graduated college also, but there is such a thing as autistic burnout and it may also be good 'insurance' for if you find yourself unable to work in the future. Ultimately, there is definitely no clear better option to getting diagnosed vs just understanding your own nature without having a label- there are pros and cons to both.