I was wondering why most E27 base LED lamps kept the traditional shape of incandescent lamp? Wouldn't like tubular shape use less material in production and on the otherhand in most fixture it would not matter what shape the lamp has unless it's too bog.

This is the shape people used to see the lamp.

Yup. Many fixtures are made with exposed lamps, so changing the lamp shape radically changes appereance. It's one of the reasons why people didn't really like CFLs.

This is even more true with so-called "LED filaments" lamps. Much of the manufacturing process of classic incandescent lamps can probably be carried over directly to that kind of LED lamp, notably the glasswork.

However in non-consumer applications the hassle or mimicking the old-school lamps is rarely justified, except maybe where it kind of happens anyway, say with LED retrofit tubes.