I'll be honest this is a hard one for me. Who's to say where the line is between too busy and not busy enough? In fact, I don't think there is a hard line, there certainly isn't in scripture; there are no commandments that say thou shall start at 8 and quit at 5 or thou shalt not work more than 40 hours a week, right? But that being said we have all felt personally, and seen others who are clearly too busy or overworked.
I look through scripture and see many warnings against laziness, I don't see many against working too hard or being too busy. Except of course that God commands us to honor the sabbath and keep it holy. So here are some thoughts, take them or leave them, about deciding for yourself where that line is between good work ethic and being too busy.
First, let's keep in mind priorities and seasons. We all have times in our lives where seasons change and this requires priorities to be shifted to allow for other things, like kids sports, college, work, etc. So there is definitely no good to be gained from judging others about their schedule. However, when looking inwardly, I like to look at my list of priorities. Which for me is God, family, ministry, work, and so on. When one of my lower teared priorities is taking time away from or eclipsing one of my higher priorities it makes me take a step back and recalibrate.
Second, I pray that church is not on par with Netflix. What I mean by that is that if church is only another entertainment piece or social activity than your probably right, your too busy for that, but, if church is really where believers get together and almighty God shows up in the middle of us and brings healing, hope, and new/eternal life to our souls than you can't afford not to be there.
So to sum it up, I guess, it depends on what church is and where it falls in your priorities. Sometimes we get stuck in a rut and church becomes another social motion to step through. My prayer for you is that church is, or will become, a vibrant life giving community in which we seek God for the lost, wait on truth together, bear one another's burdens, love unconditionally and see God show up; not just from the goosebumps on our neck, but in power with physical/emotional healings, gifts of the spirit and lives drastically changed by the power of God.