And, like many I suppose, we had a complicated relationship.
He was a mean drunk during my childhood and early adolescence, quit booze and started making an effort when I was 13 or 14 (but getting too old to really bond with him at that point), and then only saw each other when I was home for college in my early adulthood. I always appreciated how he tried to be a better dad with my younger siblings, because his effort showed how much he wanted that second chance.
That said, my parents saved nothing for retirement and 99% of my conversations with him as an adult were him calling to borrow money. It wasn't entirely his fault. He had a thriving roofing business until 2008, and now we can look back and see that (at least here in the US) basically everyone's purchasing power was permanently lowered after that. His mistake was adopting so many kids so late in life. His kindness outweighed his good sense.
He started working in the 1950's at age 11 and never stopped, supporting his younger siblings and his mom. (His father died young.) Until a few months ago he was driving with my mom for DoorDash at age 83, because that's just how cruel and uncaring the US is to people.
And, he was very sick. Two years ago he was having trouble using a seat belt and basic door locks due to mild dementia, and he once lost control of his bladder in my car, which I've lent mom and dad for the past two years. When I visited him six weeks ago, it was clear to me that he was dying. Thankfully he woke up for a bit, knew I was there, and I told him to relax because we weren't getting on the roof today.
Still, it feels more like an uncle or a distant grandparent has passed away. Not my dad. I'm really just over here glad that he's no longer in pain and wishing he hadn't lived through all this the last five years.
I will honor him for the quiet kindnesses he showed me, like when he put $1000 in my hands to pay a tuition bill in college so I wouldn't have to quit, or the times he put a blanket over me when I was a kid or carried me to bed and tucked me in, or the time when I was four when he somehow found the money to get surgery for my eyes. I'm also grateful he hired me (and six weeks later fired me) to roof one summer, with (I now understand) the intention of making sure I never chose the life he did because it's such hard physical work.
Now I just hope there's an afterlife where he gets to sit on his ass for more than five minutes and not be surrounded by a bunch of kids.
I don't know if I should say I'm sorry for your loss, because like you said, it was complicated and you're glad he's no longer suffering and struggling just to stay alive. I know exactly how you feel except it's my mom, and instead of realizing her mistakes with age, she just got worse.
Life can really be the meanest bastard sometimes, and it sounds like it dealt you both a shitty hand you didn't deserve. I'm sorry it didn't give you the father you deserved until he'd already left a permanent mark on you, and I'm sorry that life turned him into the man that couldn't be the father you deserved until it was too late to really repair your bond.
At the same time, it sounds like he really did make an effort to try to make sure you would have a life that was spent living more than just struggling and really that is one of the most primal instincts a parent can have. It doesn't make up for the damage done, but it can be comforting to know he loved you enough to want something better for you.
When you have a broken bond with a person who was supposed to be one of your first memories of love and comfort, it's pretty normal not to feel like you're grieving the loss of a parent when they die. That doesn't mean it's not painful, but you grieve the relationship you never got to have, and you had probably already been grieving it for most of your life.
I will also say it speaks to his character and yours that he really made an effort with your younger siblings and you admired him for that. You're probably right that his life would have been less of a financial struggle if he hadn't adopted so many children later in life, but it also sounds like he felt you and your siblings where what made the struggle of life worth living and staying sober.