I wouldn't hesitate using an aluminium bike etc etc nor worry about your concerns if I used the proper tyres and pressures, plus also checking your bike regularly for loosening bolts etc.
Use loctite or heavy gear to minimise loosening stuff and you'll be fine.
Again:Cannondale. If there had been a significant failure rate, they wouldn’t have been so popular.
While it’s only one example, I put mine on a weigh station scale early on during its 6,000 mile maiden voyage. 90 lbs. with gear. I was another 190. The frame did fine. Technology has improved over the last 25 years since that trip.