I gotta admit - randomized packs = Loot Crates is a definition I'm not sure I buy into. That means that the old D&D miniatures game was 100% loot crates.
And Magic the Gathering, which predates MMO's by several years, has always been "loot crates".
Jein. There are some countries that have banned "loot crates" but are conversely fine with Magic the Gathering or other collectible card games. The gist of the legal argument (as I understand it) goes that even if you don't know what you are getting in a pack of cards, you are still getting a physical product, whose contents can be valued, collected, or traded. In the case of the D&D miniatures game, you are likewise still getting a physical product.
In contrast, you do not own what you buy as part of digital loot boxes/crates for digital games. You are licensing those digital products as part of playing the game. If for some reason you are banned from a digital game by the game developers, you will no longer have access to anything that you purchased as part of that game. You do not own those goods.
There is another difference between buying packs of collectible cards and game loot boxes. The latter often inclues audio-visual enticements that are meant to be more psychologically addictive. Some of these loot boxes and gacha games are explicitly modeled after addictive gambling games like slot machines.
There are a lot of predatory practices when it comes to loot boxes in computer games and their rise is "crapifying" a lot of games right now. As in games are intentionally being designed to suck in ways so as to encourage you to bypass that suckiness with pay-to-win microtransactions in the shop.
Another separate issue that sometimes exists with online games with loot boxes or microtransactions, though not all, involves currency exchange of real world currency to a game shop currency, and the nature of the exchange rate requires that you spend more real world money than the face-value worth of the item. Moreover, using fake currencies like "Gems" are often used by companies as a way to mask and obfuscate the price of the microtransactions.
So let's say for example that a game has a cash shop that uses "Gems" as its currency. You can buy Gems with real world currency (e.g., Dollars, Yen, Euros, etc.). However, items in the shop are usually priced in a way that requires you to buy more Gems than you need to buy the items you may want. So for example, a game releases a mount that costs 2000 Gems in the shop or an armor skin for 1200 Gems, but you can only buy Gems in increments of 800 Gems for $10 or 1600 Gems for $20 dollars or 2400 Gems for $30. So to buy this game shop mount, you are likely spending $30-40 for what would be a $25 item.
You will have leftover Gems, but those Gems can only be spent in their cash shop. So if you want your value's worth for what you actually spent, you may need to buy something else in the shop. However, you may not have enough leftover Gems to buy anything that you want, which is meant to encourage further real world spending into the game shop. This is also "working as intended" as far as the game company is concerned.