It's like the only really good pure ICE powertrain that Toyota has right now is the G16E-GTS, but then again that's a GR engine, not an engine for mainstream Toyotas. A few years ago, some of us were still speculating and thinking this 2.4T is going to a super competitive engine that can easily blow the doors off its predecessor lol.
I wager if you did a double blind test without being able to watch the rev counter, 9 out of 10 buyers wouldn't be able to tell the difference between the 2GR and the T24A out on the road. Having driven Highlanders with both engines, I believe that Toyota's intention was masking that this is a turbo engine. It doesn't have the kick that I typically feel in a performance turbo.
The T24A is lighter, more efficient, packaged better, and meets more stringent emission standards than the 2GR. The 2GR FKS only met ULEV70 while the T24A meets ULEV30 just like the A25A hybrid. The 2GR largely dating back to 2005 probably had to be addressed from an emissions perspective. I expect that killing the V6 also simplified crash testing for new models. Those unsexy reasons are likely way the T24A replaced the GR. That said, the A25A hybrid very much overlaps the performance of the T24A while delivering better fuel efficiency. IMO, Toyota knows that there is a segment of buyers that are not ready to take the plunge on the A25A hybrid in a larger vehicle.
The T24A hybrid, IMO, is why the T24A exists overall. It gets rave reviews for being a really nice, smooth, substantial powertrain. Offering the non-hybrid T24A serves some purpose for the buyers that won't buy a hybrid yet and provides some economy of scale. The hybrid version covers the higher end Grand Highlander, TX, RX, Crown, etc. that really can't reasonably be handled with an A25A no matter how many electric motors you throw at it.
