I'm curious
@PhilBowles, which games do you consider to be strategically challenging or have a good AI, if any?
Very few games have especially good AI - but all I've ever demanded of this AI is that it can actually use all of the game mechanics. The inability to use aircraft remains glaring as an AI fault even though it is of rather limited gameplay significance. The AI needn't master the loyalty system, but it should at least be able to avoid being unnecessarily punished for it, by simple measures such as not forward settling and placing (and keeping) governors in low-loyalty cities where this would change loyalty pressure to positive.
As far as challenge, any older Civ titles spring to mind - and in Firaxis' current stable, X-COM (although that's tactically rather than strategically involved, and there's a fair bit of RNG involved). In general I agree that strategically challenging games need to be multiplayer, such as RTS games and Magic.
I think it'd be interesting to review them. I personally can't think of any mainstream games that would fit that category as a single player experience at the moment, while still appealing to a wide audience.
Accessibility is one thing, but at least nominally difficulty levels exist for that very reason - to cater to players of different skill and experience levels. I can't beat Civ IV at its highest difficulties, for instance, and I favoured playing Civ V at Immortal because Deity tended to demand relatively stereotyped, optimised play patterns.
Where Civ VI has gone wrong in my estimation is in drastically lowering the difficulty at higher levels of play. The game should be a sandbox for those who want to play it as such ... but not at the highest difficulties. A strategy game, largely by definition, is a game in which you need to adopt a strategy to win, and deviation from that strategy should carry penalties. Civ VI is to other Civ games what Rome II was to the rest of the Total War franchise in that respect: more or less anything goes, and while it would be unfair to say no forward planning is required, the game is exceptionally forgiving even on Deity of changing course late or making non-optimal plays.
There was a big drop in difficulty from Civ IV to Civ V, but the essential structure of the difficulty levels remained intact: as you progressed further up the difficulty ladder, you had to get a better understanding of the game's systems and play in progressively more optimal ways to succeed. I've literally beaten Deity in Civ VI without understanding certain mechanics, such as amenities, and without having any specific idea of tech progression, and that's with peaceful victories rather than through conquering the AI. That was admittedly early in the game's life and it is more difficult than it was at release, but I've still never needed to memorise tech progression or policy cards, or necessarily what certain uniques do and how to use them to best effect.
If decision-making is going to be of reduced importance, at the very least I'd rather see fewer forced decisions and unnecessary resource buckets that exist more to give you something to do on most turns instead of clicking "End Turn" than to have any real game impact.
Unfortunately this direction for Civ VI is either by design or a consequence of the fact that, as Firaxis proudly proclaims, only their own in-house 'expert' player plays the game on a difficulty as high as Emperor. Throughout the streams the devs talked about balancing disasters so they had a balance of positive vs. negative impacts, for instance, to the extent that even originally negative-only events like dust storms increase fertility in the final version. That might be fair enough, but ... the disasters have no real negative effects. This has been pointed out by game journalists, who for the most part are not experts in individual games. Climate change, RPS reports, just stops after a while and without having particularly impactful effects on the game.
All that suggests to me that the devs either have a poor idea of balancing positives and negatives, or actively want most decisions and events to have more positive than negative effects, further reducing the strategic importance of making the right ones. The same was true in Rise & Fall: they discussed giving Dark Ages both upsides and downsides, but never apparently considered downsides to Golden or Normal Ages, while the Dark Age downsides ended up being trivial (granted, so for the most part were the upsides).