ESO is a solid MMO in the Bethesda mold. Questing is ways better than most, almost no kill 20 coyotes rinse and repeat nonsense. A bunch of the game is soloable with exception of dungeons, raids, and zone bosses. Every class has tank DPS and healer specs. Most of the world scales. Dragon fought at level 5 is a tough level 5. Rats fought at level 50 are wimpy level 50. So you can go wherever you want and not be crazy bored or one-shotted.

If you buy the latest expansion (Necrom), you get all of the previous major expansions (yearly updates which add an entire new overland (and sometimes underground) zone) for free. What you do not get are the minor expansions (ie. Thieves Guild, Dark Brotherhood, Imperial City), dungeon expansions (extra dungeons and quests that lead up to or expand upon the story of the major expansions), or any of the extra little QOL things (Any Race Any Alliance, Mat Bag, Crowns, Character Slots, etc).

It's likely that Necrom will go on sale for the Steam Winter Sale, so you could get it for cheaper than 79.99 CAD -- even at that price though, you can easily sink 1000 hours into the included content and still not have finished absolutely everything. In that case, you may need to buy ESO Gold. ESO's main selling points are the fully-voice acted quests (which are almost always excellently done), expansive world with tons of hidden lore, excellent music, and the fact that everything in the game (yes even Raids!) is technically soloable.

Also, none of this requires a subscription, although there is one you can get if you wish. The sub gives you a bunch of premium currency (usable on cosmetics, QOL things like a summonable bank/merchant, houses, permanently buying extra dlcs), unlimited access to ALL dlc as long as you're subscribed, and the incredibly useful Craft Bag which gives you an infinite storage space for crafting materials. None of these things are at all required to play the game however, nor are they -- more importantly -- required to have fun!