Obviously, this is what a sensible plan (elevated, curving around developments) for this corridor would look like. But Metrolinx clearly has no intention of even considering something if it's not on-street or underground. I asked a question regarding this on the Metrolinx Engage page for the Crosstown West extension a couple of months ago (exactly two months ago today, actually), which, mind you, was far from the only question asking why the heck this extension won't be elevated, and obviously, and they responded saying "The alignment moving forward for further study balances the ease of local access and the speed of travelling, and outperforms other options in offering the best network connectivity and travel experience for people living and travelling along the corridor.", completely avoiding answering my questions about whether an elevated alignment was even considered, and having an outright false answer regarding "ease of local access and speed of travelling", given that an elevated alignment would offer the same speed of travel, or slightly slower speeds in inclement weather, and would offer better ease of local access, since the platforms are closer to street level than those currently planned.
Without much of a doubt, building this extension fully grade-separated is the way to go so it can provide faster connections to the Mississauga Transitway and the airport, but, as many others agree, using deep tunnelling is far from the best option for this, given how much more it costs and how much longer it takes to build. But in the end, the current plan is going to be the easiest to go forward with, largely because the nearby NIMBYs would get angry that this line would be an "eyesore" or, in the case of a cut and cover tunnel, that it would be "too disruptive" if other quicker to build, more cost-effective options were used instead of this one. What it really comes down to is picking between keeping the NIMBYs happy or saving somewhere in the region of $1-2 billion, and it's clear that the province has chosen the former, likely so Dougie can keep his voter base in Etobicoke.