I don't think Mediatek is to blame here at all. More reputable vendors are using Mediatek chips now, and we will see proper support for these phones. I doubt vendors like Xiaomi will not support their phones for after less than 2 years, regardless of the chip.

While it's interesting to read how Mediatek is finally up their game, they still have something vital to be fixed.

Until today, Mediatek is identical to phones that doesn't offer long time support of its OS. Very rarely a Mediatek phone received 2 official OS updates. I know it's the vendor, not Mediatek, responsibility to provide such updates, but Mediatek plays some part of it (difficult to update, etc).

Unless you plan to buy a phone and forget about it in next year, I strongly advice not to take a phone with Mediatek SoC in it.