So... not a lot of thoughts on the main topic other than to say I - in general - agree. Freakshow characters are often (but not always) a lazy way of trying to create an interesting player character. That said, an occasional game of them can be fun. I am currently using the promise of a freakshow character as a way to incentivise risk taking (in the name of heroics) in my game. The problem I run into is finding a happy balance between two extremes. Extreme one is players knowing their characters are safe (due to plot armor or DM fudging dice rolls) and therefore acting in extraordinarily risky ways. Extreme two is players knowing their characters aren't safe (due to the DM rolling in the open and taking what come) and therefore acting in extraordinarily timid ways.
My current solution is to put strict limits on character creation to create 'average' characters (for the setting). Then roll the dice and let things fall where they may. When characters die - and they probably will - I have some extraordinary NPCs on standby with easy to understand and insert motivations. The player can then (if they want to ) take over one of these NPCs as their new PC as something of a compensation. I end up with players who do not want their characters to die (as they have put time/effort to create them/flesh them out) but are not upset when those characters do die since they get a little 'reward'. I find that puts my players in the best head space. They take risks when the story seems to require it but also act to protect their characters. I've had one PC die and while the player was disappointed, he also expressed a bit of excitement to take over the wilden druid NPC. I make a point of marking these NPCs as future PC replacements when they show up in the story.
Anyway, on to XCOM style games. I get why Dan doesn't love XCOM: Chimera Squad. It does make a major retcon on the autonomy of the alien shocktroopers from the previous games and tries to turn them into (semi)-innocent victims of the ethereals (aka the overlords). Now they are trapped on earth when they didn't want to be here in the first place and you get some awkward integration storylines. I like Chimera Squad but I get why it's not everyone's cup of tea. I do have some other suggestions. Apologies if these were suggested to you in other forum, but you never know if you don't put it out there.
Gears Tactics is great. A very similar storyline to XCOM (aliens things burst out from inside the earth to take over, soldiers band together to fight back) with similar (but not identical) gameplay. I actually really like some of the differences. The fact that executing a downed opponent gives all other members of your fire team extra action points incentivises the occasional risky maneuver. It is Xbox/PC only - no PC version - but it is part of Game Pass, which means you pay no additional cost if you are already subscribed to that service.
Wasteland 3 is on my list to play next. Obviously not an alien invasion, this is a post-apocalyptic game set in Colorado. It looks to be a little more RPG with less of a big roster of soldiers to swap in and out of missions as the current objective requires. On more platforms that Gears Tactics but it is also part of Xbox Game Pass, so I won't have to pay (more) to play it once I'm done with Gears Tactics.
Phoenix Point has me very intrigued. I love everything I've seen so far. Phoenix Point during an alien invasion of earth. Players command a lone base - Phoenix Point - and try to save humankind from annihilation by the alien threat. Between battles, aliens adapt through accelerated, evolutionary mutations to the tactics and technology which players use against them. Meanwhile, multiple factions of humans pursue their own objectives as they compete with players for limited resources in the apocalyptic world. How players resolve these challenges can result in different endings to the game. The designers have specifically stated they view it as a spiritual sequel to XCOM. I am waiting for an Xbox port but it is out on PC right now if you want to give it a try. It is part of Game Pass and I hope that is still true once the console ports are out.
Mutant Year Zero is one I enjoyed for a while. Also post-apocalyptic with a smallish roster of mutants to customize and develop. It has a slightly more granular power curve than XCOM or GT did (so there are times you find your previously badass team facing very hard foes until you earn a level or two to get the skills you need to deal with them. Less customization options as the mutants you get are the mutants you get and the only thing you can really customize is their loadout and mutant powers. Still fun. Also on all platforms and it just left Game Pass so you will have to buy it outright if you want to play.
Some quick hits of 'similar' games. Invisible, Inc. is kind of a stealth take on the TBT game. Decent game. Shadowrun (Dragonfall or Hong Kong) can feel like XCOM at times but is really more of an RPG that borrows some combat ideas from the TBT genre.
Anyway, just my two cents...