Well it hasn't been nonsense for me. I'm towards the end of my career and have had 6 perm jobs in total, the last 4 at very senior levels in major internationals. Haven't had more than a one page CV for 15 years.
On a page if you can. I've spent 35 years in business, often at senior levels and can still get it on a page, with extra narrow margins :)
What you accomplished 20, even 10 years ago is of little importance. You just want it to open doors, not get you the job
Happy to take a look if you want...