Are there any proven benefits to lifting heavy weight (compared to let say having a regular physical activity such as swimming, hiking, cycling, bodyweight exercises?)
So, if you're wondering about whether lifting is good for your health, you should first identify what outcomes you're aiming for and then look for yourself what interventions increase the likelihood of those outcomes. I cannot provide specifically the information you desire in an economical way¹.
But it's unfair to just leave you with nothing, so here's a starting point in your research (apart from the Wikipedia article on Weight Training²): https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2453303/
¹ For instance, maybe you don't care to be able to run some arbitrary distance. Maybe it isn't important to you to be able to cliff dive. Maybe it isn't important to you to live to 80. Maybe you consider being muscular to be of negative utility on its own. The state space is too large for me to capture here.
² https://en.wikipedia.org/wiki/Weight_training#Health_benefit...
https://time.com/4803697/bodybuilding-strength-training/
It also increases your baseline strength, which is in turn one of the strongest correlates to maintaining health at any age.
We're not talking about crazy hypertrophy type lifting - bench 135, squat 185, deadlift 225 and you will not have rsi problems.
Ironically my RSI began within a few months of starting weight training.
Is that ok with you?
If exercise and hard work were that easy everyone would just do it and we would have far fewer problems.
Most things in life aren't some sort of instant solution. If you run you won't live to be a hundred. If you smoke you won't get lung cancer. What these actions do is shift your probability distribution in certain ways. Running frequently improves your overall life-expectancy, smoking increases your risk of lung cancer¹. You can do everything right and still have trouble. You can avoid every intervention and still have things work out.
So, if you're outcomes-oriented you modify your environment and behaviour to match the outcomes you want based on what you know to be capable. Getting vertical mice, split keyboards, expensive chairs are all interventions that shift your distribution to better outcomes. Lifting well and frequently, having better posture, taking breaks to move are also interventions that shift your distribution to better outcomes. Each intervention moves you to a better state of being.
Some interventions require you to apply techniques of willpower and motivation. Others require you to place yourself in an environment where those things aren't tested. Yet others are just tools. I think I would go out on a limb to say that most people younger than their early 30s who aim to spend themselves into good health are making moves that are rational.
Credentials here at bottom to prove I'm not some fat guy trying to justify not working out. My lift PRs indicate I'm not a novice (though not particularly exceptional). My weight at PRs (unless otherwise stated) was 165 lbs (75 kg). My height is 6' (184 cm).
Deadlift: 375 lbs at 180 lbs body weight, 3x315 lbs at 165 lbs
Squat: 275 lbs
Front Squat: 225 lbs
Clean and Jerk: 135 lbs
5k time: 23:53 (within 3 mos of the PRs)
¹ A quick test for your intuition for these events is to imagine in your head what you think the incidence of lung cancer in heavy lifetime smokers is and then look it up. 95%? 75%? 50%? 25%? 12%? 5%?