Yeah sounds like you've been unlucky with mowers. I've still got a 30+ year old Rover hand mower that still goes well. Trouble is my right shoulder hasn't been too good this year and either I pull it with the left hand, not easy, or I put up with pain or I give it a miss. Bit like yourself. I've got an old whipper snipper, except the cord head has broken, so I only use it on brush with the metal head. I bought a Ryobi battery one and it works great, only a small one & cheap, but I did all round the fruit trees a few days ago where the grass was about a foot high and it did a good job. Battery is the way to go if it does the job. May not last as long but what does.
