How relevant is Lamarckism

Jean-Baptiste de Lamarck (born August 1, 1744, † December 28, 1829)

The botanist and zoologist Jean-Baptiste Lamarck developed his own theory of evolution at the beginning of the 19th century, long before Charles Darwin. The theory that is commonly used today under the term "Lamarckism" is based on the basic assumption that animals can pass on the characteristics they have acquired in the course of their lives to their offspring. Lamarck justified his view with the environmental conditions that quasi trigger an inner need to adapt in the animals.

The most common example to illustrate Lamarck's theory is the development of the giraffe's neck. The habitat of the giraffe in the African steppes is dry and the supply of vegetable food is limited. For generations, the giraffe had to stretch for food in higher areas of the trees, which lengthened the length of the neck. The giraffes passed on their newly acquired neck length from generation to generation.
The scheme would look like this:
Need of living beings to adapt -> use of organs leads to stronger training -> acquired characteristics are passed on.

Lamarck's theory from today's point of view:
From today's point of view, Lamarckism has been refuted because the genetic makeup would have to change accordingly. This is not the case, however, since the genes do not change through the use or non-use of organs.