I know plenty of window cleaners out there who don't have a website, but they got so much work that they can barely keep up with it. Goes to show that it's more about doing your job well and a bit of networking.
On the contrary, in this day and age, it makes sense to have a website, but don't go down the rabbit hole thinking that it's the magic bullet for gaining more customers.
A website is just your online representation and unless you actively promote it via Google Ads, SEO, Facebook or whatever else, then it won't be much use to you.