Sitcoms are a modern television staple, far before WandaVision brought classic domestic sitcom hijinks to the forefront of pop culture again. Though television entertainment has evolved a lot, just like the world has since the 1950s and 60s, there's a lot about Bewitched that's timeless…however, the main points hit different to modern viewers in 2021. Namely the less than "bewitching" relationships in the show that are downright problematic. As a disclaimer, the relationships do get better as the show progresses through its 8 seasons, however, the first season is the one that cemented its popularity straight away, and it's the one that aged the worst of all the seasons.
First off, Samantha (Elizabeth Montgomery) and Darrin (Dick York, Dick Sargent): the entire premise of the show is that she gives up being a witch and her family, who are also witches, to be with the man she loves. If he truly loved her, he wouldn't take her away from her family and force her to give up all she's known and who she is. This is actually a hallmark of abuse – that's right, Darrin the human is exploiting Samantha's love for him by controlling her to an obsessive level.
Now, a mid-century housewife didn't have much agency, true, however, Darrin's control extends far beyond what's expected or appropriate for the times. A partner should never seek to cut you off from your family, friends, and support network; they also shouldn't dictate your every behavior and require you to give up a part of yourself to be with them. This method of control is abuse and is utilized by codependent, often jealous partners as a way to cut off their significant others' support network, forcing the abuser to be their only lifeline and resource. Normalizing this as a vehicle for comedic shenanigans is problematic at best and dangerously enabling abuse at worst.
On Darrin's frankly baffling anti-witchcraft "moral high ground", Endora's (Agnes Moorehead) disapproval of Darrin is amusing and all her tricks on him are well deserved, however, it's a far cry from anything resembling a passable relationship with your wife's family. Samantha is close to her mother, even if she annoys her, and Endora wants the best for her daughter – not to have her controlled by an insecure man who is manipulating her into giving up who she is. Neither party is in the right, which makes both in the wrong. Darrin shouldn't be so disapproving of Endora on the grounds she's a witch and Endora shouldn't constantly belittle Darrin (including but not limited to never calling him by the correct name).
Next, the constant gaslighting of one Gladys Kravitz (Alice Pearce, Sandra Gould). Neighborhood busybody Mrs. Kravitz is constantly spying on the Stevens and observing all of Samantha's strange magic. Her husband Abner is convinced she's crazy and won't even think about believing any of her stories, treating her like an exasperated parent treats a hyperactive, over-imaginative toddler. It's not just Abner gaslighting Gladys – Samantha and Darrin both trick Gladys into believing she's crazy as opposed to her finding out about Samantha's witchy powers. The "cranky older married couple" is a sitcom trope staple, however, it's Darrin and Samantha gaslighting Gladys that goes too far – it all starts to feel too mean after a while as opposed to harmless hilarious fun.
Compared to other similar shows of the day, Bewitched is positively regressive when it comes to its main relationship. I Love Lucy showed a healthy partnership between Lucy and Desi – not without its problems and shenanigans, but it's a sitcom staged for comedy. I Dream of Jeannie also features a main relationship where the male exerts control, but the dynamic of her being a genie that's conscripted to him while her being allowed to use her powers within the confines of the supernatural rules (as opposed to her husband's).
All in all, Bewitched is still absolutely enchanting, though viewed with modern sensibilities, it's a little less romantic and a little more "shouting at your TV at midnight because watching sweet people be brainwashed by abusive relationships is hard". The premise of Bewitched is adorable, though if I were married and told my new husband I had the power to make a drink appear in his hand whenever, or lock the door from the comfort of our bed, you better believe he would be crazy about powers like that instead of completely outraged.