I earned Companion Pass this year after getting my first new travel card in a decade, the Southwest premier card. I didn't go out of my way to earn it, just happened by chance with their 60k sign up promo in June. I have a Southwest business visa card and was thinking of getting rid of that since they are getting more strict about what you can put on the business card (they say due to business regulations), so I got the personal card with plans to get rid of the business card.
Ironic thing is I can't even make use of my Companion Pass much because most of my family / friends still work 9-5, kids in school, etc. So I'll be traveling solo most of the time anyway.
While I have Global Entry / TSA pre-check, I wouldn't go out of my way to sign up for travel cards / game the system. If I tried I could really make rewards, but it's not worth the hassle for me personally. The bonuses would be an insignificant of my income / expenditure, and not worth my time personally.
If it's worth it to you, go for it.