It is the truth. WWHD had a brand new lighting engine and higher resolution. That's it. No work was done on textures, models, geometry etc. The game looks better because it simply aged much better than TP.
TPHD had all textures entirely reworked, most models redone, new lighting, better resolution, actual new content, there are new assets and models added for example to enhance sceneries (they added trees, vegetation in some parts). There has been much more work put on TPHD than WWHD, that's a fact.
Because those changes weren't necessary, as you said WW aged very well and those textures and models still look good for 2013. TP HD just needed more changes to make it look like a 2016 game. Even those changes you mention like better geometry were done half-heartly. I mean cool that the door in Malo Mart features more polygons, but Link's gauntlet and the Eldin bridge still look as blocky as before. On the lighting side, it
needed a brand new engine with modern features like in WW HD. Lighting in TP HD was changed a bit, they reduced bloom made stuff brigher, but what it needed was a complete overhaul with all the features I mentioned before (especially dynamic shadows and bump mapping on the new textures.)
Anyway, we are going off topic here. It's nice that TP HD worked for you, but personally I needed more and I'm still disappointed that TP HD wasted so much potential to make it look like a modern game.
Maybe we can agree that Metroid Prime Trilogy should be better than both remasters!
This, point that WW HD looks better doesn't mean that TP HD is bad port, simply WW aged much better.
It's not a bad port, but a port that left much to be desired. Adding new lighting= graphical overhaul of the game. WW HD looked so great because they added dynamic shadows and global illumination, not just because WW has a timeless art style.
I mean I think that TPHD looks like trash and WWHD looks gorgeous. But you just can't argue that WWHD had much work on it or even more "heart". WWHD was done in six months. TPHD took two whole years! It was just objectively a much bigger work and of a bigger scale. They were simply coming from way lower than with WW.
That's fine. I also like WW's art style more. AFAIK TP HD was done by Tentalus, a pretty small studio whereas WW HD was done internally, so that development time seems logical. I wouldn't argue that it was a bigger project because of a longer development time.
What you want is a remake, not a remaster
Yes, but in that regard, WW HD is much more of a remake than TP HD for me.