There is a very simple answer for this but there is almost no solution unless you rethink your entire website building strategy.
To loads your website it requires 279 (!!!) requests.
Our demo requires only 60.
It means that your website will load at least 5 times slower than our website and there are so insanely many scripts added in your website source that browsers has no idea what to render and in which order.
Just should get rid of at least half of your plugins and scripts to solve anything. Needless to say that no buyer will wait 10 or more second on each page load and of course Google will never rank you on top because your website is much, much slower than others.
Unfortunately, I can’t help you with this one.