I admit that when put to paper it does sound a bit less attractive and some refactoring might be needed, but you have to keep in mind that the value of a single point does go up as you advance, rather than diminish.
The game looks to be targeting around level 30 as endgame(level 8 is ~25%), and those extra 10 points will, combined with gear and other sources, still add up to nice chunk of your power.
As an example, an average D&D campaign has you start with about 70, depending on how you split them in point buy, and you only get 5 extra before you hit level cap.
I sometimes forget that DnD offers that many stats / Since most of the time you cannot give yourself lower than 10 or 8 in at most 1 stat. So functionally you're investing 10-16 depending on the point buy. In the most recent addition you are now offered a +2 or +1/+1 every four levels. So it's 10 stats given by leveling with roughly 15 points invested at start.
My math is all assuming that the base stats remain with a 'bottom' floor of 10 (or pretty much 0) So in that case you'd be investing 20 points (using 60 of your suggested 80 to give your character the minimum of ten in each.)
In this case our math isn't all that different. I was suggesting that instead of the DnD point buy, stat points instead offer diminishing returns not based on level but by current stat, in math that closely reflected the point buy seen in DnD character creation. (i.e 2 points invested from 13 and up to get the equivalent benefit of 1 stat at 8-12 as opposed to DnD 5e where it costs 2 points to get one stat at 13+ but only one point to get a stat at 8-12)
And I'm suggesting they keep that math ( similar to the point buy you use at DnD character creation) throughout the entire experience and offer more stat points (similar again to the +2 in one or +1 in two of DnD). Which is very similar to the way DnD does it but wouldn't require a change to as many numbers. Hopefully, the amount of stats given by items and everything else remains relatively untweaked (3 stats/level and 66% of that currently offered on gear)
Sorry for all the brackets. tl:dr our ideas may only be different in presentation and how important we want gaining 1 level to be to the process.
For example:
I invest some number (I'm doing less at the start, so 5) of stat points.
All stats offer static and nice looking bonuses to the things they should offer bonuses to (mostly agreed upon already in this thread) up until your character has more than 5 invested (or 15 solid number) So say you put all five in INT. at level two you get 3 (3!) stat points. Say you want to increase int and start giving yourself some finesse. You put one point in int and 2 in finesse. The 2 in finesse are worth the nice shiny bonuses they would have been worth at creation. But the 16th int (the 6th point invested) only gives HALF (or 2/3rds?) the static and nice looking bonus. So you get another level and decide that the next three go all into Finesse to get yourself to 16 INT/15finesse and take advantage of all those shiny 10-15 full bonuses. Now level 4? You can further diversify by putting points somewhere else but you've fallen behind a pure INT by (6-(6/2)= 2 full static bonuses in two levels!
I'm hoping that a system like that would provide fun shiny meaningful decisions each level and allow for a variety of builds. (also encourages more stat spreading while still rewarding having a main stat)