So there's a mechanic in the base game where to start quests you have to wait X hours in real life. And to unlock those quests to start the timer, you need "power" which is gathered from doing side quests or clearing a repeatable encounter. Combine this with all of the grinding stuff like gathering herbs and unlocking fast travel spots everything is a drag.
There are mods to reduce or even remove those requirements I listed so it's up to you how "cheaty" you want to get. I essentially removed the timer, doubled my power and XP gain, and removed the harvesting animation (honestly the best mod). Even then, after only doing main story quests, what I felt were important side quests, and like half of the companions quests, and only the final dlc to see the true ending, it still took me 55 hours...
Best I can say is start it up and when the game dumps you into the first map, only do the main story quests and then move onto the next zone. Because each map honestly probably has its own 55 hours of picking up rocks and killing bandits.
It is pretty cool seeing stuff you did in the old games relate to what is going on now in the game.. But I feel like they didn't expand on it enough for it to be solely the reason to play the next two games. The biggest highlight is morrigan and leliana, who both have a big role in 3. Alistair kinda pops up every now and then, and the rest are non-existent in the other games besides passing mentions. Same situation for your companions in DA2, one is returning companion in DAI, others are like oh remember them?
I would say the biggest decider on whether or not it's worth is if you performed the ritual with morrigan. However, the result of that is kind of just swept under the rug since it seems like they were predicting they were gonna use that in the next DA game. But since the original DA4 got scrapped and there's no real save import for veil guard and I'm sure the choices they allow you to make to are only the huge ones like morrigans ritual, it seems kind of pointless. To me, games like this shine when they remember the small details, a minor npc you thought was cool and randomly pops up again later on.
Ultimately my advice is the same as above; watch a YouTube summary, or if you're feeling really frisky, read the DA wiki on the people you're interested in.