So your advisor sucks. Now what?
One of the truthiest truths about grad student supervision is that very, very few people are explicitly trained in it. So faculty members get jobs, bring on students, and then....have no real sense of how to mentor a student other than how they themselves were mentored. So many students find themselves with a mentor that doesn't fit their needs. But once you realize that your advisor isn't what you need.......then what?
Step One. Accept that it isn't fair, and that it is a systemic issue. This is an important step because most graduate students I know working with supervisors that are not good fits internalize that on some level. They work harder to try and please an unplease-able critic. They hide their diverse career plans because they sense they won't be supported. They take advice they know doesn't fit their values or their life because it seems disrespectful or sneaky to ask for a second opinion. If your advisor only reads the work of the person in your lab who is "on deck" to graduate, that isn't a fair system - you all deserve feedback. If you worry about your funding disappearing if you reveal something about your personal life or future plans, that isn't fair - it doesn't have any real bearing on the work you're doing in the degree. These issues are pervasive, and they often have everything to do with how the supervisor understands their role, and little to do with any individual student. It isn't fair, it sucks, it actively hurts graduate students, and more than likely, you didn't do or say anything to cause the situation. (This isn't to put all the blame on individual advisors either - when you produce exponentially more PhDs than there are available tenure track jobs, it fundamentally changes the purpose of the degree, and mentorship has to change along with that, and few supervisors are trained in how to support students through a degree that looks nothing like they one they received. This is an academia-wide issue.)
Step Two. Identify what you need. So once you've accepted that your advisor isn't supporting you in all the ways you need to be supported, it is tempting to generalize: they're just a terrible advisor and there's nothing to do about it. But often, digging through to a more nuanced understanding can be really helpful. Maybe they're extremely thorough careful readers of your writing, but they don't really know how to support your career plans. Maybe they're incredibly supportive of your health and allowing you to build a flexible work schedule, but there is no real structure in place to make sure that you're on target to graduate when you want to. Dig in and figure out what areas really need support - your graduate school experience is complex, and needs to be supported in a lot of areas. The more you understand where you need the support, the easier it will be to find it.
Step Three. Empower yourself to get the help you need. It is so hard to say: this isn't working, and I need more help. But if you can get to a point where you want to do well in grad school and beyond MORE than you want to never need help, it becomes easier to ask for the support you need. Ultimately, unless your advisor is a magical unicorn, you will need additional support that they cannot give. This is especially true because only you can zoom out and see the entire picture of your life; only you know where you want to be in five or ten years, or what things are incredibly hard to achieve, or what your health and wellness is. It is hard to remember when everyone is trying to keep up a perfect image for the eventual job market, but the number one goal in graduate school is to complete the degree, not to complete the degree without needing any support from anyone ever. So if your goal is to complete the work, why not ask for the things that will make that easier? Why not build up the team of mentors, support, and resources you need to get where you want to go, in the way that makes the most sense for your life?
It would be great if academia were a system that was inclusive, where support was offered freely and a diversity of goals and experiences were anticipated and planned for. Many of us are working actively to make that happen. But until then, the biggest danger is not bad advisors. The biggest danger to graduate students is the belief that your entire fate rests in their hands. It doesn't. Working to support yourself so that you can do your best work is a skill that will pay off forever - and now is a great time to start.