The page has to open on a dying phone in a house with no power
Your site is fast on office fiber and on your own laptop, which is the one place it does not matter.
Picture the actual visit. Somebody is standing in a warm house on a phone at fifteen percent, on mobile data, possibly because the power went out and Entergy has not restored the block yet. The hero video does not play. The web font never arrives. The number they needed was below three screens of animation.
Cut weight until the first screen is text, a phone number and one compressed image. Serve modern image formats, size them for the device, and lazy load anything below the fold. Self host the fonts or use system fonts.
Test on a mid range Android over a throttled connection rather than on a new iPhone over wifi. The gap between those two experiences is where most contractor sites lose calls they never learn about.
Make the phone number a tap target, keep it visible while scrolling, and do not hide it behind a chat widget. Chat is fine as an addition. It is a poor substitute for a number somebody can press with one thumb.