Actually... with some VPS's, you can have "dedicated" resources for it... you end up paying quite a bit more for them though.
Dedicated vCPU
Shared vCPU
My site (based upon simple visitor loads) would be well served by shared hosting... this has 5 sites running on it.
But then you count in the fact that I'm using ElasticSearch for my XF site (ran on the VPS) along with Redis cache and Memcached (for different sites)... I couldn't do that on shared hosting. I would have to pay for outside vendors to connect to... and if I'm going to do that, then why not simply host it myself.
I started out (for about 2 months over a decade ago) on shared... and, as I've commented before, I quickly kicked it to the curb as I was competent to administer my own servers and I didn't like the restrictions.... so I chose to do go to a VPS, then to dedicated servers with my own VPS instances, then back to VPS's as I could not realistically justify the cost of dedicated hardware when my other hobbies could use that money.
You still can have incidents of "slowdown" on a VPS, especially if it's a cheap hosting provider that oversells - which many of those "low dollar" ones tend to do.
This is a 12 year old CPU, but honestly, it will run most everything a base site would need.... and you get the "dedicated hardware" for about twice what my VPS runs.
The thing that keeps me from it, it's based in the EU... I prefer my server to be US based. This is an offer of an "old" server that was taken out of service by Hetzner and offered at a "special" price. OVH has recently got "stoopid high" on their server prices, or I would look at them.