You're either lucky or have a heavy right foot ! Google maps reckons St Albans to Birmingham is 1h 50m and that's 95 miles - if you're doing it in sub 90 mins, you're running an average speed of over 60mph and that's pushing it a bit.
That foot isn’t as heavy as it used to be, now that there are cameras almost the whole way. But an average speed of over 60mph is easily doable, even with the roadworks.
To travel to Liverpool, Manchester, the North Wales coast (and, for most time of the day, anywhere north of Warrington) starts with a journey to Milton Keynes to join an Avanti service, and around half an hour after leaving Northampton one can catch a glimpse of the town's landmarks again, as you finally start to head towards your destination. Of course, this extra travelling doesn't come free; ticket prices for all these destinations are the same as, or slightly more expensive than, one fro Milton Keynes.
Even more bizarre is that, at some times of the day in the normal timetable (and, I think, once an hour in the Covid one) NRES
suggest travel via Rugby ('separate tickets may be needed').
I wouldn’t say it’s bizarre, it is simply the nature of the rail network. There are plenty of places where to head in one direction, it is usually quicker to head the opposite direction first. Almost everywhere on the WCML south of Watford heading anywhere north of Rugby outside the West Midlands, for example. Or more pertinent to me, to get to Derby, Nottingham or Sheffield I leave home, walk to St Albans station, catch a train to St Pancras, then catch an EMR northbound where I will see my house approximately 80 minutes after I left it. In my case driving is clearly quicker. But I choose the train as overall it is better.