Google is reporting that websites have got faster in the last year, saying that: “We observed improvements across the whole web ecosystem.” I don’t think this is unrelated to the fact that page speed has become a ranking factor. While it’s probably true that millions of web site owners have improved the loading time of their sites, don’t forget that much of the web’s traffic comes via Google, so if faster sites are promoted in the results, those will get more visits and the overall effect is that ‘the web gets faster’.
I have several zero-budget sites, mainly on WordPress, which are infuriatingly slow. I don’t have the commercial justification to sort this out, but for business sites, there’s no such excuse. Use Page Speed Insights and any other tool available to suggest ideas to improve your site’s response speed. If your website developer can’t implement these and get clearly measurable results, maybe find someone who can.