Slow mobile websites are a business problem, not engineering
More than 50% of all website traffic has been mobile since 2017 (ref). I can relate to this statistic looking at my own browsing habits. I do most of the web browsing on my smartphone. Even when a laptop or TV with a larger screen is a few meters away. For me, convenience outweighs reduced screen size.
Unfortunately, very few businesses relate to the shifted web browsing trends. Most business websites have not progressed beyond responsive layout. For a small part, it might be due to general lack of good craftsmanship in the web dev field, but for the most part it boils down to business priorities, because good performance and good UX does not come for free.
It’s not like there is a lack of evidence that good website performance leads to better conversion rates (ref). Every time the website is closed, because it took too long to load or content continued to jump for a few seconds, a customer is lost. Lost business and damage to the brand should be enough to put mobile website performance and UX a business priority.
I think the first step to improvement and alignment of business priorities is measurement. Measure website performance, measure conversion rate, measure bounce rate and most importantly measure user experience. With quantifiable metrics in place, it becomes easier to judge different investments and their impact to the bottom line. Identify things which work and do more of them. Also identify things which sounded like a great idea in the meeting room, but have zero or negative impact on the key metrics and remove them from your website.
Measure, Optimize, Measure, Repeat