Ancient-Red-Dragon: More like, it's a way to cut corners and cheap-out. 2018 is late enough into gaming history to stop accepting such things, especially with the publication of games like Divinity Original Sin 1 & 2 which both feature massive amounts of full voice-acting.
Cut corners? It's a both a design and budget decision. Having some lines non-voiced allows for having the same line having several variations which are chosen depending on factors like reputation and past actions. You get different lines of dialogue depending on if you're known as "benevolent" or "aggressive", or people will or will not refer to you have yet completed the "save the village" quest. I found this pretty impressive playing PoE.
The next thing is that the same line of text might need different readings depending on the situation: An NPC might be relieved (if you are known as benevolent hero) or shaking with fear (if you are known as cruel thug). In writing this is easily established by a single paragraph at the start of conversation. With VO you would need to have the same line spoken several times with different inflection - or use a "neutral" VO - which could actually be detrimental to the experience.
While maybe the total amount of text in one playthrough is roughly the same in PoE and D:OS 2, the total amount of possible lines is several times higher in games like PoE. Although I read somewhere, that while the number of dialogue steps is comparable in PoE and D:OS 2, what's three lines in latter are more like three paragraphs in the former...
And then there's the problem that good voice acting costs... There's things like budget and time to consider. Not to mention that once VO is recorded the lines are pretty much set, while no VO allows for tinkering and polishing the dialogue until release.
So in the real world you simply can't have everything, you have to make concessions to time and budget restraints. Game designers have to make decisions what they are aiming for (in this case either a tremendously complex dialogue system or full VO).
It's fine to voice your opinion that you are not happy with the decision and would like they had done things differently. Accusing the devs of "cutting corners" is not.