Why have MTB tyres with strong front / back design disappeared? Back a few years ago was easy to find tyres with a particular design based on their position, back or front, see this sample image fron a pair of Nokian Boazobeana:

Riding with those was pretty nice, especially with the front one, which provides a great driving precision and security.
So it's strange why is so hard to find something similar in the market today, someone knows why?
They haven't
https://www.schwalbe.com/en/mtb-reader/eddy-current-rear
&quot;FRONT:
• Reliable cornering grip paired with high braking traction.
• Excellent transmission of steering corrections throughlong grip edges even when less weight is on the front wheel in ascents. The result: Understeer is more controllable.
REAR:
• Maximum propulsion and braking traction throughmassive blocks that transmit sufficient power to the ground, even on the steepest climbs.
• Hard wearing thanks to large-volume center studs.&quot;
https://www.schwalbe.com/en/mtb-reader/racing-ray
&quot;RACING RAY
THE FRONT WHEEL SPECIALIST. The completely new, extra aggressive XC profile paired with the versatile Addix Speedgrip compound makes Racing Ray a XC weapon and an ingenious addition to Racing Ralph.&quot;
Also
https://www.schwalbetires.com/bike_tires/off-road_tires/fat_albert_front_477
Also given that rolling resistance is more important at the back due to weight distribution, it's common for riders to mix tyres, so you don't really need a 'front' and 'rear' tyre designated as such, you can just choose two different tyres - a harder compound and/or less grippy pattern at the back, and a softer compound with more knobs at the front. Also different tyre widths is common.
See e.g. here
https://www.mbr.co.uk/news/product_news/best-mountain-bike-tyres-323130