One: the words
Read your homepage and your main service page as if you were a customer who was told to look.
Does it describe the business you run now, or the one you ran when it was written? Businesses change what they sell, who they sell it to, and what they are good at, and the site is usually the last place that gets updated. If you have added a service that now pays the bills, or dropped one that does not, the words are already out of date.
Then check the language. Businesses drift into describing themselves the way competitors do rather than the way customers ask. If a customer would call it a rebuild and the site calls it a digital refresh, that gap costs enquiries.
Last, find where you tell someone how to enquire, and notice how long that took. Failing this check on its own is usually the cheapest outcome on the page. Words can be rewritten in the site you already have.
Two: the structure
Pick the thing people most often ask you before they buy. Try to answer it using only your site.
If you cannot get there in two or three moves, the structure is working against you. The common failures are a site whose pages match an old shape of the business, one that has grown an extra page every year until nothing is findable, and one that has a page for everything except the question people actually ask.
There is a version of this failure that looks like a words problem. If the answer exists but is buried in a paragraph three pages deep, the writing is fine and the structure is not.
Three: who holds the accounts
This one is different in kind, because it does not matter how the site reads if you cannot change it.
Check who holds the domain, the hosting, the files and the logins. If the site only runs on a platform you cannot take with you, or the accounts sit with a designer you no longer work with, then leaving is a rebuild whether or not you wanted one.
Do you own your website? walks the five checks properly. If the answer is that you are renting a builder, a hosted builder, or a site you host covers what you would and would not keep.
I put this last because it is the least visible and the most likely to decide the answer on its own.