Daily contact lenses have several advantages. They:

- don't accumulate gunk over days/weeks/months that can cause injury and/or infection

- are cheap to replace if torn or lost (which happens with tiny transparent things)

- are made from softer, thinner material (because it doesn't need to last) which is way more comfortable

My monthly lenses work great, and the only way I can tell that they’re in is the fact that distant objects are clear.

Dailies were a vast improvement in comfort and convenience for me over permanent lenses that required cleaning and storing overnight.

Permanent lenses had also led to some blood vessel overgrowth due to lack of oxygenation.

Using a new pair everyday does make quite a few tricky problems go away downside being slight extra cost and extra plastic pollution.

There's R&D pushing both ends to higher performance - dailies and monthlies. Dailies reduce chance of infection vs. putting in the same contact over and over 30 days in a row, and provide the highest quality vision every day because the contact degrades over 30 days of use.

Meanwhile on the monthly side of things, contacts that are approved for "extended wear" have enough oxygen permeability to be worn overnight now. Ten years ago, this was for up to 7-14 days (Biofinity), now they are up to 30 days (Air Optix Night & Day). This also greatly reduces the chance of infection (because you're not handling the contact 60 times per month) and is just super convenient because it's nice only having to touch your eye 12 times per year - you largely forget you're even shortsighted at all because you can see clearly from the moment you wake up till the moment you fall asleep every single day.

If anything, I'd argue that the monthly ones are the "scam" pricing, not the daily ones. They're priced just about the same per year, but the manufacturing costs must be significantly lower when you're only consuming 1/30th the number of units.

Regardless, the market appears to support ongoing R&D for both strategies.