Cost effectiveness
They say it's to expensive because frankly it is.
Did that math several times on here and gave reason why welded tubs are generally not that big of a deal to 90% of the population.
No matter if it is a welded tub, splittable tub or separate bearing cross design, if you do not do it yourself, forget about bearing or spider replacements being worth it.
A whole tub assembly is significantly more expensive compared to just the bearings.
A good set of bearings plus seal will set you back 40-80$ approximately.
A spider can actually be had for certain Samsung or LG models at 80-120$.
A whole tub assembly (like Electrolux) is 200$ upwards, usually more like 300-400$ after shipping.
However, removing the bearings from most designs is quite a job.
There are a few newer exceptions.
Some second to last Gen Gorenje (EU brand) washers still had metal tubs with bearing crosses; Miele's W1 design isn't to dissimilar.
You can just take the back of, take of the belt and pulley, then undo the bearing cross with the drum and tub remaining in the machine.
That takes a skilled technician 10min tops, so a bearing change is a 30min thing.
However, on everything else, you have to remove the entirety of the tub assembly from the machine and then split the tub.
That means either removing the entire bottom (pump, piping, shocks etc.) plus all the counter weights.
Then slide the tub out, split the tub.
Change bearings and back.
On sealed tub designs you usually save the whole tub splitting thing.
Point is, any way, you are paying about 500$ AT LEAST to get it professionally done.
I say at least since usually, you need 2 tech visits (diagnosis and ordering parts plus return visit) and pricing is conservatively estimated.
800$ is not far from basically any new washer.
One interesting design over here are the AEG/ELux H-axis TLs.
They have bearing units conceptionally not unlike what you would find on those huge Milnor industrial washers.
The bearings sit in a plastic housing that is fitted to the tub as a separate piece.
There are points for a wrench to attach to.
A pair of bearings is 50€ or so.
You remove the side panels, remove belt and pulley on the one side plus the grounding lead.
Remove bearing, screw new one in.
Depending on if the tech has them handy that repair is done in like 20min.
200-300€ total.
But a very easy DIY repair since you don't have to handle bearings and parts are cheap.
Here a video that illustrates the simplicity of the operation: