Two decades of plugins
Why run WordPress on a VPS instead of shared hosting
WordPress asks very little of a server. A recent PHP, a database and a web server covers the whole requirement, which is part of why it runs 41.2% of all websites. What a VPS changes is the ceiling. You get CPU and memory nobody else is touching, the PHP version you picked and a caching layer you chose rather than one the host chose for you.
Root access is the other half of it. Redis object caching, a staging copy on a subdomain, WP-CLI running from cron, a firewall rule in front of wp-login.php: all of that is yours to set up. Nothing sits on a plugin blocklist. Several sites can share the same server too, which is where the maths starts working for anyone running more than a couple of installs.