For the gram weenies this category of gear may never exist as these are definitely not "need to haves" more just "love to haves". Choosing to bring luxury items with you isn't a bad thing and if it helps you enjoy your thru hike and keeps you motivated to continue it is well worth the added weight.
Slowly this is moving from the "luxury" section and into the safety and security needs for a thru hiker, these are the devices like the Bivystick
and Garmin InReach Mini. Their purpose is to be able to text updates to family when you don't have cell signal and to be able to signal rescue services should a life threatening problem occur.
I thought these were silly for the longest time, but have come to love my pillow more than I would have ever expected as it leads me to much improved sleep. Most are at best a couple ounces and you need to have restful sleep, if you haven't tried on I suggest giving it a try as it can be a blessing.
For some of us older hikers the prospect of sitting on the ground or finding random logs to sit on isn't too pleasant of a thought. Thankfully there are a lot of good lightweight chairs that exist on the market today like the Helios Chair Zero
While many may balk at carrying an extra pound or so on the trail those same people will be envious at the camp at the end of the day when you can sit in comfort warming up near a fire while not getting dirty on the ground.
Everyone has some gear items that they personally just feel like carrying, whether they need the to feel safe or just want to bring. I definitely won't tell you to carry useless gear when at all possible as ounces become pounds, but you do you and HYOH.