You're conflating two different topics:
1. "Its easy to find many examples of apps that were challenging to build even just 10 years ago, that are somewhat trivial now."
Correct. It's easier now to build apps that we used 10-15 years ago.
2. "Do you agree or disagree that techproducts today are easier to build than 15 years ago?"
Incorrect. Tech product complexity has increased in many ways in the last 15 years (and the increase in complexity is larger than the decrease in complexity we talked about above).
-- Regulation. COPPA regulations strengthened significantly around 10 years ago. Europe's GDPR went into effect in like 2016. Those are just a couple popular ones. Remember when Amazon just didn't collect sales tax? Sure makes things easier! And remember, those laws are constantly changing. If NJ raises their sales tax, you better have someone paying attention. If Europe comes up with a new privacy law, you better have enough people to drop everything and implement everything that's needed.
-- Scale + globalization. Myspace topped out at like 100 million active users around 15 years ago. Facebook is 30 times that size now! That scale comes with complexities most don't think about. How do you report user video ad income to the IRS-equivalent in Andorra? I don't know, but you now need to know at Facebook's scale!