I am not going to cover the typical discussion regarding the diminished lifelong earnings of Ph.D graduates as I don't think everyone is optimizing their life 100% around money. If that's the case I would recommend looking holistically including choice of life partner and their earning potential as well where you live and the job market there.
I have a PhD in Computer Science from one of the top 5 schools in the world and Masters from unknown university in a medium size city.
Through the years I have struggled with being an outlier at my unknown university where people did not understand my passion for CS. I took part in open source projects, went to meetups and read tons of CS books just to satisfy my curiosity. at the same time there was nobody I could talk to regarding my passion.
When I entered Ph.D this turned out to be the greatest social experience ever. Almost all my current friends I have met during Ph.D. They are geeks in their own respective area (CS, Chemistry, Biology, Social Science, Theatre studies) and we can talk for hours about our research which never happened with me before. I met my life partner there and chances of finding of someone who I can talk to about theorem proving in a "normal" world are close to zero. On top of it she also understands the value of hard work and long hours I commit to work which has always been a struggle with my partners from general population.
Now the bad parts. You should expect that Ph.D. is a long and lonely journey that you have to execute by yourself. You are likely to go for months without any tangible results and you need to be happy with that. I did not suffer any mental health problems during the Ph.D. but they were fairly common between my friends due to pressure to publish and loneliness of the pursuit. If during Masters you are already dealing with some anxiety Ph.D. may not be enjoyable. In the end all my friends turned out fine and graduated but expect ups/down during the process.