People always say Ruby is dead, but there are quite a few companies are (partly / fully) using Ruby (and Ruby on Rails):
18F
500px
Airbnb
AngelList
Archive Of Our Own
Apple
Artsy
Authy
AWAY
Basecamp Why
Bloomberg
Buildkite
Calendly
Chatterbug
Codecademy
Cookpad
Coinbase
Discourse
DoorDash
Dribbble
Elastic
Etsy
Fastly
fiverr
Forem (Formerly DEV)
Flexport
Gumroad
Goodbits
Goodreads
GOV.UK
hatchbox
Harvest
Heroku
Hulu
Instacart
Intercom
Kickstarter
Lobster
Mojosass
MUNA
Netflix
Netlify
GitHub
GitLab
Gusto
Pinterest
Procore
Product Hunt
RedHat
Soundcloud
Shopify
Speee
Square
Strava
Stripe Why
Twitch
Zendesk
ZEUS
& Ruby Companies in China, Singapore, and Taiwan.
As of 2020.03.08.
See also: Top Ruby Companies.
Ruby on Rails is no. 3 (1.45%) in Programming Language Usage Distribution in the Top 1 Million Sites
Ruby on Rails is no. 3 (4.17%) in Programming Language Usage Distribution in the Top 100k Sites
Ruby on Rails is no. 3 (6.63%) in Programming Language Usage Distribution in the Top 10k Sites
Web Framework by Wappalyzer Ruby on Rails is 9.5%.
Many people using it does not mean you should or it’s the best choice. But it shows that Ruby does work for them and you could spend more effort to explore with Ruby.
I think the biggest reason people choose it is because it is productive, especially in the early days of your business.
Ruby is definitely fast enough to get your ideas out to the world.