no mobiles or computers to undermine plots
This is such a sad take imho.
Like, you know (and I'm sure I could find) someone in the 1960s was thinking "I should set this in the 1890s before cars and telephones ruined all the good plots!", and some bro in the 1890s was thinking "I should set this in the 1700s before that blasted telegraph and steam trains ruined all the good plots!".
Like, if you're in your 60s or 70s, maybe, and you can't really "think modern", or imagine how a situation could play out with computers and mobile phones properly, like you're going to leave holes in the plot because of them, then I can see you needing to set things in an earlier era because of that. Fair play in that case. But if you're under 50, and you can't figure out how to write good plots with those things existing, and even to utilize them, then that's a bit silly and imho sad/disappointing. Mobile phones came in when I was a teenager, the internet came in when I was a teenager. I'm 46, man, I had a mobile phone (a crappy one but one) and was using the internet when I was 16 (possibly 17 for the mobile). That's 30 years ago.
I do kind of get this for TTRPGs, because that's because you don't control over the plot, and players are incredibly resourceful. But when you have full control over the plot, you can fully account for mobile phones and computers and the internet! Plenty of modern spy shows and thrillers do - just look at Netflix or Prime - Black Doves, The Night Agent, The Diplomat, The Agency, Reacher, etc. etc.
Hell, some of them even rely on such tech and are better, cleverer shows because of it, like The Capture (which doesn't always get it 100% right but like, good enough man).
Ironically I think the actual one thing that gives some writers (but not others!) real problems, especially ones in their 50s and older isn't mobile phones per se, nor computers, nor smartphones, it's text messages, a tech that's been in common use since the 1990s, and that they definitely use themselves. So many writers rely on this crutch of people not picking up their phones, but like, who the hell phones someone? Boomer-ass behaviour! That's such a weird thing to do most of the time, unless you're going for a long conversation with someone (even then you'd videocall a lot of the time, we do live in the future after all, that's one bit of futuretech we actually got!). You send a text message. Even if you want to warn someone, if they don't pick up, you send a text message. It takes a fraction of a second to read a short text message, too, literally less time than it would to pick up the phone and be told the same thing (and anyone under about 50 can probably type it extremely fast too).