ARIMA gives Trend (or Regression) - can see its slope (that reflects speed of change dx/dy)...
LSTM gives MovingAverage - posessing curvature & slope in each moment - that can characterize not only speed but also acceleration changes to up or down
p.s.
in all times Lines in e.g. classical supply-demand charts in economics were considered to be Static Models (as all regressions), and Curves on such charts (instead of lines) reflects Dynamic Models (showing not only speed but also acceleration)