Thought I'd relate my experience.  I've had most of my Christmas lights on dimmers for years,  but last year took it a bit further.  I had my trees on X10 controllers that had dimming capability, but they were spotty at best.  Last year I pretty much eliminated X10 and went with Smartthings modules. Unfortunately they do not have built in dimmers, so I made up a cord with a simple electrical box and one of the half dozen or so dimmers I pulled out when I  updated to smart dimmers.

When I put my trees up I always replace any burned out bulbs, and this year I was amazed.  My dining room tree has just short of 500 miniature bulbs and I only had 12 burned out!  Usually it's 30 or so.   Same in the living room, about 400 bulbs on that tree and only 5 burned out bulbs.  You do sacrifice  some of the sparkle, I run them at about 90% brightness, but I do also same a bit of energy.  I think the big help is the "soft"turn on, the bulbs are not hit with full voltage initially.

My light strings are easily 35+ years old.  They are the hard to find 9-12" spacing between bulbs.  When I put them on the tree each light is set next to the branch and the wire is looped over the light holding it in place. Take a bit of time but for me well worth it.