This is the worst advice someone could give. It absolutely is ok to decide on your own if it's good for you and the others if you attend or not. I wouldn't want anyone to come to my funeral just because others expect him to.
This isn't how death works
A funeral is not 'some event' that you can just skip for your own benefit. That's not what it's about.
“It's just tons of sad people.” - this makes you sound like you have the emotional acuity of a 4 year old. You can fix that, but you can’t do it sitting in front of your computer.