It's complicated, take it material by material.

The one that's closest to a scam is plastic. Virgin plastic is made from oil industry by-products, so in most places it's a lot cheaper than recycled material and tends to be better quality, because it's hard to properly sort composite resins. It tends to end up overseas somewhere in Asia, despite ongoing efforts by governments on both sides to end the practice. Burning the plastic to generate electricity is in many places labelled as 'recycling' but to me it's not, it's just efficient incineration. In British Columbia we take it a little more seriously, where RecycleBC is responsible for ensuring recycled material generally stays within the province, tracks the amount that is successfully recovered and generates reports on recycling's efficacy, but it means people here sort plastic containers, flexible plastics and all separately.

Glass is not really a scam, there are two ways it gets recycled. In places like Mexico, glass bottles are returned, cleaned and reused. Most other times, glass bottles and jars are crushed into silica, which can then be heated into another glass shape again, so the main cost is heat.

Aluminum (pop cans) are one material that is easy to recycle and cheaper and far less environmentally impactful for industry to use than from new refined bauxite, no real difference in quality. Steel cans (think soup cans) are good as well, and generally metal material recovered from larger items at scrapyards is recycled for profit.

Recycled paper is fine, it does save trees if you care about them. Recycled paper tends to become things like cardboard boxes and bathroom tissue, as quality does deterioate each cycle. I've been by a paper recyling plant, it stinks a lot of the time but I know they do good work there.

Organics are not recycling, these do successfully become mulch a lot, but anyway the word "compostable" is a bit of a scam and not regulated well. Especially those compostible utensils and bags, they may compost in very specific conditions, but don't just disappear if you leave it on the ground or in the water.

In any case you'll want to also consider the cost of transporting, sorting and processing when recycling. That's why reduce and reuse are better ways to reduce impact compared to recycling. So while there usually is a benefit to recycling, when it's emphasized particularly by pop bottle companies and oil funded entities, it's kind of a guise to get you to consume more plastic. I think that's why people call it a scam.