Not all cryptocurrencies are deflationary. Yes the deflationary model encourages holding/discourages spending however for some projects this is a desired outcome based on the utility the coin/token is aiming to provide.

Additionally deflationary crypto can act as a hedge against inflation, hyperinflation, and stagflation. The decreasing supply can counteract inflationary pressure caused by externalities like government policies and economic shake ups.

cryptos like BTC or ETH that can be mined with ASICs

ETH moved to proof of stake, no more POW mining needed.

The intrinsic value of any art is what someone is willing to pay for it.

For example the world’s most expensive NFT, The Merge by Pak, sold for $91.8 million. Its price was higher than the sale of Jeff Koon’s Rabbit, the most expensive artwork by a living artist at auction. It’s all about personal tastes and how deep folks wanna dig in their pockets with this stuff.

I buy a picture from you on an NFT marketplace, I get an NFT proving I bought it. What value does an NFT provide in this case?

In this case, assuming you’re a trader in this example, you’d be banking on whatever art you purchased to gain further value so you can then sell your certificate of ownership and make a profit. This is no different than art sales/trades IRL. Here’s an art gallery owner discussing using NFTs as certificates of ownership for real world art sales and the added benefits over traditional COOs.

The truly decentralized portions of the market can’t be directly regulated. A feature not a bug as the point of decentralization is a trustless environment with no overlords, middlemen or gatekeepers.

The places regulation can touch are endpoints: fiat on/off ramps, legal entities (companies, orgs) operating in the space, people’s freedoms in regards to the ability to interact with crypto etc. Regulating those endpoints in an attempt to manage the decentralized interior requires a level of nuance and respect for people’s privacy and liberty that first-world governments have so far yet to demonstrate.

In lieu of sweeping regulations (which can have many downsides), the “web3” industry would be well served to get it’s act together internally with tech solutions to problems like rug pulls, scam tokens, wash trading and such. The example of fiat markets shows such problems can’t be completely eliminated but if tech solutions can eliminate just some or most of them that’d make the playing field safer by orders of magnitude.

Note to any unware: “Trustless” in this sense means the ability to transact without having to “trust” any outside authority to regulate, allow or manage the transaction for you. Everything programmatically handled and equally open to inspection and validation by all involved.

…is there any solution to prevent scalping?

Built-in price ceiling and verifiability. Resales could be limited or completely forbidden as well.

Just wanted to mention fractionalized NFTs are a thing. That “can’t be subdivided” part doesn’t hold for all types.