The amount of traffic a website can handle is a function of cost not experience.
Even without a CDN you can host the static files in a bucket for practically free.
Heck even serverless platforms usually give you 1M function calls for free each month.
Cost is not the limiting factor.
Sadly I have been noticing non optimized sites at lot more now.
the amount of traffic a website can handle is impacted by both. with insufficient experience, website won’t scale, money won’t be spent.