Conquest takes way too much time and makes me want to quit

I understand where you are coming from but I'm gonna have to disagree here. I think the availbility of play-time has been significantly reduced since almost everything has become simmable and if it's not simmable, battles can be put on auto and I can pick up my phone almost anywhere in the world log in and put a battle on auto and since I go to the bathroom daily, I can finish almost everything in available in that short time. 

There are a couple of factors that you should consider:

1. This is a mobile/video game. The intention is to enjoy the game and the purpose of games is to spend time playing the game (can't say CG is helping players enjoy the game but that's another issue)
2. You are provided solo events, guild related events and everything has rewards to help you progress your account. 
3. You are offered to spend money on the game that can significantly help you progress your accounts and make events easier. 
4. Guild events (TB/TW/Raids) are a commitment you are making of your own free will. If you find your guild is to strict regarding participation, you are free to leave the guild and apply to another guild that suits your play style more. 
5. Guild events are not daily occurances. Raids require 180k tickets and is a 3 day event and you have a maximum 5 battles you can do. TB is twice per month and has 6 Phases and during each phase you have a limited amount of CMs and SMs available affected by various factors (that can almost all be solved with money) and all those battles can be played normally or via auto battle functions (there are guides on the internet that can tell you which toons you need so you can full auto those battles). TW is also twice per month with 3 phases for 24 hours and depending on how you play it requires no effort at all (place everything on D) or a lot of time (use everything on O) or in between if you decide to do both. 
6. Solo events have no required participation. This includes daily quests, Coliseum, monthly events, Squad Arena, Fleet Arena, GAC and also specifically  CONQUEST. Yes you can skip doing everything if you don't feel like it but more importantly, you can choose how you participate in them and still recieve some rewards which brings us to the most important aspect of this:
7. Maximum rewards require effort. It sounds pretty much like you want to spend almost no time at all to play the game, spend a minimum amount of time and effort, and still be rewarded?

Conquest participation is up to you. Put in effort and your rewards are better. Spend money and you make it much easier. You can even choose lower difficulties and accept lesser rewards. Sorry bro but in a game that functions around money, making this request is pretty short sighted.

Pick a guild that suits your playtime need, spend money if you wish to progress faster and make the game easier for you to play, sim what you can, auto battle what you can. Choose what non-required events you decide to participate in and adjust your own expectasions on what rewards you will be able to get in accordance with the amount of time you are willing to spend on playing the game. If you want maximum rewards? Put in effort. There is no participation trophy for every body. 

Besides, to be honest, even during Conquest with other events occuring, I can myself finish half the stuff when I'm taking a dump. Since the removal of Galactic Challanges (stupid decision) there is a limit to what you can do in the game unless you spend crystals or money. You can't even battle test your teams and new characters without either sacrificing available attempts or risk losing a battle with the negative consequences that follow (GAC and TW for example). Conquest is the only event where you can test new toons/modding etc without the risk being too significant over the 14 day event time. 

BRING BACK GALACTIC CHALLANGES!!!

I definitely feel this way about raids and TB (OK not that I want to quit, but it takes too much time).  Maybe, in TB we could have things become simmable once you've done it say....5 times.  And raid you have saveable scores?  I really dislike having to repeat what I have done 30 or more times again and again.  

Conquest though, it's not as repetitive and I feel it's more personal (you personally get out what you put in).  Though I will definitely concede it is very time consuming, especially that first day.

My tastes for PvE might be a little odd.  Conquest is my favourite PvE game mode and.........(said in a very slight whisper)  I prefer Coliseum to Galatic Challenges!!!

If you go for Gold Crate instead of Red it's WAY easier and less time consuming and you still get the new conquest toon within 5 months, IIRC, or 6 months if you spend all your conquest credits on Signal Data and Relic mats instead of on the hot new shards. 

Remember that it's just a game. The idea is to have fun. If your current strategy is efficient at achieving some goal or other, but sacrifices fun along the way, then it's the wrong strategy. 

Do the fun thing, whatever that is for you.